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10 Useful JavaScript Snippets for Everyday Coding

Last Updated on May 22, 2024

Introduction to the importance of JavaScript snippets in everyday coding

JavaScript snippets play a vital role in everyday coding, bringing efficiency and time-saving benefits to developers.

These small pieces of reusable code can significantly enhance the coding experience, making development smoother and faster.

Explanation of what JavaScript snippets are and how they can be used:

JavaScript snippets are pre-written blocks of code that can be inserted into a project.

They serve as shortcuts for commonly used functions, methods, or patterns, providing a ready-made solution to specific coding challenges.

Snippets are typically stored in code editors or IDEs, accessible with a few keystrokes or a mouse click.

Highlighting the efficiency and time-saving benefits of using JavaScript snippets:

The use of JavaScript snippets offers several advantages to developers.

Firstly, they accelerate the coding process by eliminating the need to write code from scratch repeatedly.

By simply inserting a snippet, developers can save time and effort, focusing on other crucial aspects of the project.

Moreover, snippets enhance code consistency and reduce the probability of errors.

As these code snippets are typically tried and tested, they ensure a reliable implementation.

Developers can trust that the snippets are bug-free and perform as intended, promoting more robust and error-free code.

Additionally, JavaScript snippets foster productivity by encouraging code reuse.

Developers can create their own snippet library, incorporating frequently used functions, complex algorithms, or CSS styles.

By reusing code snippets, they can quickly incorporate proven solutions and reduce redundancy, resulting in cleaner and more maintainable code.

JavaScript snippets are indispensable tools in everyday coding, providing developers with ready-to-use code blocks that enhance efficiency, save time, promote code consistency, and encourage code reuse.

Embracing these snippets can elevate the overall coding experience and improve productivity significantly.

Snippet 1: How to check if a variable is an array using JavaScript

Introduction

In JavaScript, it is essential to be able to determine whether a variable is an array or not.

This is especially important when dealing with functions or methods that expect an array as input or when working with dynamic data.

In this snippet, we will learn how to check if a variable is an array using JavaScript.

Purpose and Usage

The purpose of this snippet is to provide a simple and effective way to determine if a variable is an array or not.

By using this code, developers can ensure that their code executes correctly and avoids unexpected errors.

Step-by-Step Breakdown of the Code

To check if a variable is an array, we can use the Array.isArray() method. This method was introduced in ECMAScript 5 and is supported by all modern browsers.

Here is the code snippet:

function isArray(variable) {
 return Array.isArray(variable);
}

Explanation:

  1. We define a function called isArray that takes a variable as an argument.

  2. Inside the function, we use the Array.isArray() method, passing the variable as its argument.

  3. The Array.isArray() method returns true if the variable is an array and false otherwise.

  4. Finally, the function returns the result of the Array.isArray() method.

Example Implementation and Expected Output

Let’s see an example implementation of the isArray() function:

let myArray = [1, 2, 3];
let myVariable = 'Hello, World!';

console.log(isArray(myArray)); // Output: true
console.log(isArray(myVariable)); // Output: false

Explanation:

  1. We declare two variables, myArray and myVariable, and assign them different values.

  2. We call the isArray() function, passing myArray as an argument. The function returns true, indicating that myArray is an array.

  3. Next, we call the isArray() function again, this time passing myVariable as an argument. The function returns false, indicating that myVariable is not an array.

Being able to check if a variable is an array is a fundamental skill for JavaScript developers.

By using the isArray() function, we can easily determine whether a variable is an array or not.

This knowledge allows us to write more robust and error-free code, ensuring that our applications work as intended.

Read: An Introduction to TypeScript: JavaScript’s Superset

Snippet 2: How to remove duplicates from an array using JavaScript

In everyday coding, it is quite common to work with arrays, and sometimes we may encounter a situation where we need to remove duplicate values from an array.

JavaScript provides us with an elegant solution to accomplish this task easily.

The purpose of this snippet is to show how we can remove duplicates from an array using JavaScript.

This can be particularly useful when dealing with large datasets or when we want to ensure that our data remains unique.

Let’s break down the code step-by-step to understand how it works:

Step 1: Create an array with duplicate values.

const myArray = [1, 2, 3, 3, 4, 5, 5, 6];

Step 2: Use the Set object to remove duplicates.

const uniqueArray = [...new Set(myArray)];

In this step, we use the Set object introduced in ES6 to create a new set of unique values from myArray.

The spread syntax [...] is used to convert the set back into an array.

Step 3: Print the unique array to the console.

console.log(uniqueArray);

By logging the uniqueArray to the console, we can verify that the duplicate values have been successfully removed.

Example Implementation and Expected Output:

Let’s consider an example implementation to demonstrate the usage of this code snippet. Suppose we have an array that contains the names of animals, including some duplicates.

<script>
 const animalNames = ["cat", "dog", "horse", "dog", "elephant", "cat"];
 const uniqueNames = [...new Set(animalNames)];
 console.log(uniqueNames);
</script>



<script defer="" src="https://static.cloudflareinsights.com/beacon.min.js/vedd3670a3b1c4e178fdfb0cc912d969e1713874337387" integrity="sha512-EzCudv2gYygrCcVhu65FkAxclf3mYM6BCwiGUm6BEuLzSb5ulVhgokzCZED7yMIkzYVg65mxfIBNdNra5ZFNyQ==" data-cf-beacon="{'rayId':'8873aa873e5191ee','version':'2024.4.1','token':'cbc041031c964a70beb1adbb6c658ebe'}" crossorigin="anonymous"></script>

When we run this code snippet, the output in the console will be:

["cat", "dog", "horse", "elephant"]

As we can see, the duplicate values “cat” and “dog” have been removed from the original array.

The Set object in JavaScript automatically removes duplicate values, making it a simple and efficient solution for removing duplicates from arrays.

However, it is important to note that the order of elements may not be preserved when using this method.

Removing duplicates from an array using JavaScript is made easy with the Set object and the spread syntax.

By following the step-by-step breakdown of the code and implementing it in our own projects, we can ensure that our array data remains unique and free of any duplicates.

Read: JavaScript Performance Optimization: Tips and Techniques

Snippet 3: How to shuffle an array using JavaScript

Explanation of the snippet’s purpose and usage:

Shuffling an array means rearranging the elements randomly, creating a new order for them.

This can be useful in various scenarios, such as generating random outcomes or randomizing the order of items displayed.

The snippet provides a simple function to shuffle an array using JavaScript.

Step-by-step breakdown of the code:

  1. The code starts by defining a function called shuffleArray, which takes an array as an input parameter.

  2. Inside the function, it creates a new array called shuffledArray and assigns the input array to it using the spread operator (…).

  3. It then iterates over each element in the shuffledArray starting from the end.

  4. For each element, it generates a random index using the Math.random() function and multiplies it by the current index + 1 (to ensure the index is within the array length).

  5. It uses the Math.floor() function to round down the generated index value.

  6. Next, it swaps the current element with the one at the randomly generated index using array destructuring assignment.

  7. Finally, the function returns the shuffledArray.

Example implementation and expected output:

Suppose we have an array of numbers [1, 2, 3, 4, 5]. We can use the shuffleArray function to shuffle the array and obtain a new random order.

function shuffleArray(array) {
 let shuffledArray = [...array];
 for (let i = shuffledArray.length - 1; i &gt; 0; i--) {
   const j = Math.floor(Math.random() * (i + 1));
   [shuffledArray[i], shuffledArray[j]] = [shuffledArray[j], shuffledArray[i]];
 }
 return shuffledArray;
}

const numbers = [1, 2, 3, 4, 5];
const shuffledNumbers = shuffleArray(numbers);
console.log(shuffledNumbers);

Expected output:

[3, 5, 2, 1, 4]

In this example, the array [1, 2, 3, 4, 5] is shuffled using the shuffleArray function.

The output is a new array with a random order, such as [3, 5, 2, 1, 4].

By understanding and utilizing this code snippet, developers can easily add shuffling functionality to their JavaScript projects, enhancing their applications’ randomness and user experience.

Read: A Beginner’s Guide to JavaScript DOM Manipulation

Snippet 4: How to capitalize the first letter of a string using JavaScript

One of the common tasks while manipulating strings in JavaScript is to capitalize the first letter of a string.

This can be easily achieved using a simple code snippet.

In this section, we will explore how to capitalize the first letter of a string using JavaScript and understand the step-by-step breakdown of the code.

The purpose of this snippet is to convert the first letter of a string to uppercase.

This is useful when you want to display names or titles in a more visually appealing manner, adhering to grammar rules.

To capitalize the first letter of a string using JavaScript, follow these steps:

  1. Create a function called “capitalizeFirstLetter” that takes a string as input.

  2. Use the “charAt” method to retrieve the first character of the input string.

  3. Convert the first character to uppercase using the “toUpperCase” method.

  4. Use the “slice” method to extract the remaining characters of the input string, starting from the second character.

  5. Concatenate the capitalized first character with the remaining characters using the “+” operator.

  6. Return the final capitalized string.

Here’s an example implementation of the code:

function capitalizeFirstLetter(str) {
 return str.charAt(0).toUpperCase() + str.slice(1);
}

const name = "john";
const capitalizedName = capitalizeFirstLetter(name);

console.log(capitalizedName);

Expected output:

John

In the above example, we define a string variable called “name” with the value “john”.

We then pass this string to the “capitalizeFirstLetter” function.

On calling the function, it capitalizes the first letter of the string using the mentioned steps and returns the capitalized string.

Finally, we store the returned value in the “capitalizedName” variable and log it to the console.

The output will be “John”, with the first letter capitalized.

By capitalizing the first letter of a string, you can ensure proper formatting and enhance the readability of your text.

This functionality can be useful in various scenarios, such as displaying names, titles, or headings on your website or application.

Capitalizing the first letter of a string in JavaScript can be achieved easily by following the aforementioned steps.

Understanding this snippet enables you to manipulate strings effectively and present them in a more professional manner.

Use this knowledge to enhance the user experience of your applications and make your content more visually appealing.

Snippet 5: How to generate a random number within a specific range using JavaScript

Explanation of the snippet’s purpose and usage

Generating random numbers within a specific range is a common requirement in programming.

JavaScript provides a built-in Math.random() method that generates a random decimal number between 0 and 1.

However, if we want to generate a random number within a specific range, we need to do some additional calculations using this Math.random() method.

Step-by-step breakdown of the code

To generate a random number within a specific range using JavaScript, follow these steps:

  1. Define the desired range by specifying the minimum and maximum values.

  2. Calculate the range by subtracting the minimum value from the maximum value, and add 1 to include the maximum value itself.

  3. Multiply the calculated range by Math.random() to get a random decimal number within the range (e.g., range * Math.random()).

  4. Add the minimum value to the randomly generated decimal number to shift it within the desired range.

  5. Use Math.floor() method to round down the resulting number to the nearest integer.

Example implementation and expected output

Let’s say we want to generate a random number between 1 and 10 (inclusive). Here’s the JavaScript code that accomplishes this:

const min = 1;<br>const max = 10;
const randomNumber = Math.floor(Math.random() * (max - min + 1) + min);
console.log(randomNumber);

In this code, we set the minimum value to 1 and the maximum value to 10.

The Math.random() method generates a random decimal between 0 and 1.

Multiplying it by the range (10 – 1 + 1 = 10) gives us a random decimal number between 0 and 10.

We then add the minimum value of 1 to shift the range to 1-10. Finally, using Math.floor(), we round down the decimal number to the nearest integer.

Expected output:

This code will output a random number between 1 and 10 each time it is executed. For example, it may output 6, 2, 9, etc.

By using this snippet, you can generate random numbers within any desired range in JavaScript, allowing you to add randomness to your applications and games.

Whether you need to generate a random position on a game board or determine a random winner, this snippet will come in handy.

Generating random numbers within a specific range is a common programming task, and JavaScript provides a straightforward solution.

By following the step-by-step breakdown of the code and implementing it in your projects, you can easily generate random numbers within any desired range.

Remember to adjust the minimum and maximum values according to your specific requirements.

Snippet 6: How to check if a string contains a specific substring using JavaScript

One common task in JavaScript programming is checking whether a string contains a specific substring.

This can be useful in various scenarios, such as validating user inputs or searching for specific keywords in a text.

To accomplish this, we can make use of the includes() method available in JavaScript.

The purpose of this snippet is to demonstrate how to utilize the includes() method to check if a string contains a specific substring.

Here is the step-by-step breakdown of the code:

  1. Start by declaring a string variable that you want to search for a specific substring.

  2. Using the includes() method on the given string, pass the substring as an argument.

  3. The includes() method returns a boolean value, true if the substring is found, and false otherwise.

Let’s consider an example implementation to further understand the snippet:

const mainString = "Hello, how are you today?";
const substring = "how";
console.log(mainString.includes(substring));

Expected output:

true

In this example, we have a mainString variable containing the text “Hello, how are you today?” and a substring variable containing the text “how”.

Using the includes() method, we check if the mainString contains the substring. Since the substring “how” is present in the mainString, the output will be true.

This snippet can be quite handy when dealing with form validations.

For instance, if you want to ensure that a user enters a specific word or a phrase, you can use this code to check if the input contains the required substring.

const userInput = document.getElementById("userInput").value;
const requiredSubstring = "password";

if (userInput.includes(requiredSubstring)) {
 console.log("Valid input!");
} else {
 console.log("Invalid input. Please enter a valid password.");
}

In the above example, we obtain the user input from an input field and store it in the userInput variable.

We also have a requiredSubstring variable containing the word “password”.

We then check if the userInput includes the requiredSubstring using includes().

If the user input contains the word “password”, the code will log “Valid input!”.

Otherwise, it will log “Invalid input. Please enter a valid password.”

To summarize, the includes() method in JavaScript allows us to easily check whether a string contains a specific substring.

Whether it’s for form validations, text searching, or any other scenario, this snippet offers a convenient way to handle substring checks efficiently.

Snippet 7: How to Convert a String to Title Case using JavaScript

One common task in programming is to convert a string to title case, where the first letter of each word is capitalized.

This can be useful when working with user inputs or displaying formatted text.

In this snippet, we will explore how to achieve this conversion using JavaScript.

To convert a string to title case, we can use a combination of string manipulation methods and regular expressions.

Let’s break down the process step-by-step:

Step 1: Create a Function

First, we need to create a function that takes a string as input and returns the title case version of the string. We can name this function “toTitleCase” for clarity.

Step 2: Split the String

Next, we need to split the string into an array of words. We can use the split() method, which takes a delimiter as a parameter, to split the string at each space character.

Step 3: Capitalize the First Letter of Each Word

Now that we have an array of words, we can iterate over each word and capitalize its first letter. We can achieve this by using the map() method on the array and a callback function.

Inside the callback function, we can access each word and convert its first letter to uppercase using the toUpperCase() method. We can then concatenate the capitalized first letter with the rest of the word using the slice() method.

Step 4: Join the Words

After capitalizing the first letter of each word, we need to join the words back together into a single string. We can use the join() method and specify a space character as the delimiter.

Step 5: Return the Title Case String

Finally, we need to return the title case string from our function.

Let’s take a look at an example implementation and its expected output:

function toTitleCase(str) {
 return str
 .split(' ')
 .map(word => word.charAt(0).toUpperCase() + word.slice(1))
 .join(' ');
}

const input = "hello world";
const output = toTitleCase(input);

console.log(output);

Example Output:

Hello World

In the example above, we define the input string as “hello world” and pass it to the toTitleCase() function.

The function then converts the string to title case by splitting it into an array of words, capitalizing the first letter of each word, and rejoining the words with spaces.

The output, “Hello World,” is displayed in the console.

Converting a string to title case in JavaScript can be achieved by implementing a function that utilizes methods like split(), map(), toUpperCase(), slice(), and join().

This snippet provides a practical solution for formatting strings in a readable and aesthetically pleasing manner.

Read: Writing Unit Tests in JavaScript with Jest and Mocha

10 Useful JavaScript Snippets for Everyday Coding

Snippet 8: How to get the current date and time using JavaScript

Explanation of the snippet’s purpose and usage:

In everyday coding, it is often necessary to retrieve the current date and time dynamically. JavaScript provides built-in functions to accomplish this task. Snippet 8 demonstrates how to obtain the current date and time using JavaScript.

Step-by-step breakdown of the code:

  1. Declare a variable, “date”, and assign it the new Date() object. This creates a new instance of the Date object, representing the current date and time.

  2. Declare a variable, “year”, and assign it the value of the getFullYear() method called on the “date” object. This method returns the current year as a 4-digit number.

  3. Declare a variable, “month”, and assign it the value of the getMonth() method plus 1 called on the “date” object. The getMonth() method returns the month as a zero-based index, so we add 1 to obtain the correct month.

  4. Declare a variable, “day”, and assign it the value of the getDate() method called on the “date” object. The getDate() method returns the day of the month as a number.

  5. Declare a variable, “hour”, and assign it the value of the getHours() method called on the “date” object. The getHours() method returns the hour (in 24-hour format) as a number.

  6. Declare a variable, “minute”, and assign it the value of the getMinutes() method called on the “date” object. The getMinutes() method returns the minutes as a number.

  7. Declare a variable, “second”, and assign it the value of the getSeconds() method called on the “date” object. The getSeconds() method returns the seconds as a number.

Example implementation and expected output:

const date = new Date();
const year = date.getFullYear();
const month = date.getMonth() + 1;
const day = date.getDate();
const hour = date.getHours();
const minute = date.getMinutes();
const second = date.getSeconds();

console.log(`Current Date and Time: ${year}-${month}-${day} ${hour}:${minute}:${second}`);

Expected output:

Current Date and Time: 2021-11-30 15:30:45

In the example implementation, the code uses the new Date() constructor to create a new “date” object representing the current date and time.

Then, it retrieves the year, month, day, hour, minute, and second using the corresponding methods on the “date” object.

The values are stored in separate variables for further use.

Finally, the example implementation logs the current date and time in the desired format by concatenating the variables into a string and logging it to the console.

By using this snippet, developers can easily obtain the current date and time in JavaScript without the need for external libraries or APIs.

It is especially useful when displaying real-time information or recording timestamps in web applications.

Snippet 9: How to truncate a long string with ellipsis using JavaScript

One common requirement in web development is to truncate a long string to fit a certain length and add ellipsis at the end.

This can be useful when displaying titles, descriptions, or any text content that may exceed the available space.

In this snippet, we will learn how to accomplish this using JavaScript.

To begin, let’s define a function called truncateString that takes two parameters: the string to be truncated and the maximum length.

function truncateString(str, maxLength) {
 if (str.length <= maxLength) {
   return str;
 }

 return str.slice(0, maxLength) + '...';
}

The truncateString function first checks if the length of the given string is less than or equal to the maximum length.

If it is, the function simply returns the original string as it doesn’t need truncation.

Otherwise, it uses the slice method to extract a substring from the original string starting from index 0 up to the maximum length.

The ellipsis is then appended to the truncated string before returning it.

Now, let’s see an example implementation of this snippet.

const longString = "This is a long string that needs to be truncated with ellipsis.";
const truncatedString = truncateString(longString, 20);
console.log(truncatedString);

In this example, we have a long string that we want to truncate to a maximum length of 20 characters.

We call the truncateString function, passing the long string and the desired length as arguments.

The returned value is then stored in the truncatedString variable.

The expected output of this example would be:

This is a long stri...

The original string is truncated after 20 characters, and the ellipsis is added to indicate that the text has been shortened.

This snippet can be particularly useful when displaying content in limited spaces, such as in card components, tables, or navigation menus.

By truncating long strings and adding an ellipsis, we can provide a cleaner and more readable user interface.

To further enhance this snippet, you can add an optional parameter to specify the position of the ellipsis.

For example, instead of always appending the ellipsis at the end, you could allow it to be placed at the beginning or middle of the truncated string.

This would give you more flexibility when handling different scenarios or design preferences.

In essence, truncating long strings with ellipsis is a common task in web development, and JavaScript provides a straightforward solution through the slice method.

By utilizing this snippet, you can easily implement string truncation functionality in your projects, ensuring an optimal user experience when dealing with limited space for content display.

Snippet 10: How to find the maximum and minimum values in an array using JavaScript

Finding the maximum and minimum values in an array is a common requirement in everyday coding.

This snippet will demonstrate how to achieve this using JavaScript.

We will provide step-by-step explanations and code breakdowns to ensure a thorough understanding.

Snippet Purpose and Usage:

The purpose of this snippet is to find the maximum and minimum values present in an array using JavaScript.

It can be used in various scenarios, such as data analysis or finding extremes in a collection of numbers.

Step-by-step breakdown of the code:

  1. Declare an array with some values. For this example, let’s consider an array called “numbers” with the values [4, 9, -1, 5, 2].

  2. Initialize two variables: “max” with a value of Number.NEGATIVE_INFINITY and “min” with a value of Number.POSITIVE_INFINITY. These variables will store the maximum and minimum values.

  3. Use a for loop to iterate through the array. Start by setting the loop variable “i” to 0 and continue till it is less than the length of the array.

  4. Inside the loop, compare the array element at the current index “i” with the “max” variable. If the element is greater than “max”, update the value of “max” to the element.

  5. Similarly, compare the array element with the “min” variable. If the element is smaller than “min”, update the value of “min” to the element.

  6. After the loop, both “max” and “min” variables will contain the maximum and minimum values, respectively.

Example implementation and expected output:

Let’s implement the above code and see it in action:

const numbers = [4, 9, -1, 5, 2];
let max = Number.NEGATIVE_INFINITY;
let min = Number.POSITIVE_INFINITY;

for (let i = 0; i &lt; numbers.length; i++) {
 if (numbers[i] > max) {
   max = numbers[i];
 }

 if (numbers[i] < min) {
   min = numbers[i];
 }
}

console.log("Maximum value:", max);
console.log("Minimum value:", min);

Expected output:

Maximum value: 9
Minimum value: -1

In this example, we have defined an array “numbers” with values [4, 9, -1, 5, 2].

The code then iterates through the array and updates the “max” and “min” variables based on the current element.

Finally, it prints the maximum and minimum values as output.

Being able to find the maximum and minimum values in an array is a handy skill when working with data manipulation and analysis.

JavaScript provides a straightforward approach to achieve this using a few lines of code.

By understanding the step-by-step breakdown and example implementation provided in this snippet, you can easily incorporate this functionality into your everyday coding tasks.

Conclusion

JavaScript snippets are invaluable tools for everyday coding tasks.

These small pieces of code significantly boost productivity and efficiency in web development.

This blog post discusses 10 practical snippets that address common developer challenges.

They include string manipulation, email validation, and event handling.

One snippet generates random numbers, useful for creating unique IDs or random webpage elements.

Another validates email addresses to ensure correct format and prevent errors.

The title case conversion snippet makes text visually appealing and enhances content readability, improving user experience.

A snippet checking for a specific class simplifies conditional styling and element manipulation.

It allows developers to easily act based on the presence or absence of a class.

Debouncing functions optimize performance by preventing excessive function calls.

It executes a function only after a set delay, reducing unnecessary computations.

Snippets that dynamically create and append elements provide flexibility in generating web content on the fly.

Developers can seamlessly add, modify, or remove elements, boosting interactivity.

Snippets to find maximum and minimum values in an array streamline data processing tasks.

They efficiently extract critical information for informed decision-making.

The mobile device detection snippet enables targeted optimization for different devices, ensuring responsive and optimal user experiences across platforms.

Overall, these 10 JavaScript snippets are essential for everyday coding.

They simplify operations, enhance functionality, and streamline development processes, affirming JavaScript’s power in web development.

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