Camel case is a widely used naming convention in programming where the first word starts with a lowercase letter and each following word begins with an uppercase letter. This style is frequently applied in JavaScript for naming variables, functions, and methods. Examples of camel case in action include variables like getUserInfo, fetchDataFromAPI, and userName.
What is a Camel Case?
Camel case is a style of formatting a string where the first word starts with a lowercase letter and subsequent words start with uppercase letters, with no spaces, underscores, or other separators between the words.
As an illustration:
- Converting the text "hello world" results in "helloWorld."
- The process of transforming a string into camel case is known as "convertStringToCamelCase."
In the realm of programming, languages such as JavaScript commonly utilize camel case to denote variables, functions, and method names. This convention enhances readability without sacrificing brevity.
Why Change to Camel Case?
There are several situations where converting strings to camel case is helpful:
- Variable Naming : The usual JavaScript practice for naming variables and functions is camel case. Using userName rather than user_name, for instance.
- Consistency : Changing snake_case or kebab-case strings to camel case when working with data from APIs guarantees adherence to JavaScript standards.
- Enhancing Readability : Camel case guarantees that variable names are easy to understand by avoiding the use of spaces or underscores.
Methods to convert camel case
To transform a string into camel case, the initial step involves changing the first character of the string to lowercase. Following this, any characters succeeding a space are converted to uppercase. Camel-case strings are utilized to generate descriptive variables.
The following are JavaScript methods for converting a string to camel case:
- Using the str.replace method
- Using reduce and split method
- Using the Lodash _.camelCase Method
- Using Array.map and Array.join
- Using a combination of String method
- Using Regex and Callback Function
Using the str.replace method.
To convert the first character of a string to lowercase, you can utilize the replace method. For the subsequent characters following a space, they can be converted to uppercase. The toUpperCase function is employed to switch a character to uppercase, whereas the toLowerCase method is used for converting to lowercase.
Examples
Below are examples demonstrating the process of converting a string into camel case.
Example 1:
The following example demonstrates the transformation of a string value into camel case by utilizing the replace method in JavaScript.
<!DOCTYPE html>
<html>
<head>
<title> How to convert string to camel case in javascript </title>
</head>
<body style = "background-color:beige;">
<h3> How to convert string to camel case in javascript </h3>
<p> Using the str.replace() method </p>
<button type = "button"
onclick = "displayData();">
Click Here to display Camet case data.</button>
<p id = "demo" style = "color:red;"></p>
<script>
function displayData(){
// string with spaces
let str1 = 'String is converted to camelCase';
//use method to convert a string into camel Case
function camelCase(str) {
// Using javascript replace method with regular Expression
return str1.replace(/(?:^\w|[A-Z]|\b\w)/g, function (word, index) {
return index == 0 ? word.toLowerCase() : word.toUpperCase();
}).replace(/\s+/g, '');
}
//get output of the camel case
console.log(camelCase(str1));
document.getElementById("demo").innerHTML = camelCase(str1);
}
</script>
</body>
</html>
Output
The output shows the camel case of the string.
Example 2:
In this example, we demonstrate how to convert a string value to camel case in JavaScript by utilizing the replace method in combination with the toLowerCase and toUpperCase methods.
<!DOCTYPE html>
<html>
<head>
<title> How to convert string to camel case in javascript </title>
</head>
<body style = "background-color:beige;">
<h3> How to convert string to camel case in javascript </h3>
<p> Using the str.replace() method with the uppercase and lowercase methods </p>
<button type = "button"
onclick = "displayData();">
Click Here to display Camet case data.</button>
<p id = "demo" style = "color:red;"></p>
<script>
function displayData(){
// string with spaces
let str = 'String is converted to camelCase Using Replace method';
// Using javascript replace method with regEx
function camelCase(str) {
return str
.replace(/\s(.)/g, function (a) {
return a.toUpperCase();
})
.replace(/\s/g, '')
.replace(/^(.)/, function (b) {
return b.toLowerCase();
});
}
//get output of the camel case
console.log(camelCase(str));
document.getElementById("demo").innerHTML = camelCase(str);
}
</script>
</body>
</html>
Output
The output shows the camel case of the string.
Using reduce and split method
Utilize the reduce function to iterate through the characters of the string and transform them into camel case. Transition the character to uppercase with the toUpperCase method and to lowercase with the toLowerCase function during the process.
Example
The demonstration illustrates the transformation of a string value into camel case by utilizing the reduce and split functions in JavaScript.
<!DOCTYPE html>
<html>
<head>
<title> How to convert string to camel case in javascript </title>
</head>
<body style = "background-color:beige;">
<h3> How to convert string to camel case in javascript </h3>
<p> Using the str.reduce() and split methods with the uppercase and lowercase method </p>
<button type = "button"
onclick = "displayData();">
Click Here to display Camet case data.</button>
<p id = "demo" style = "color:red;"></p>
<script>
function displayData(){
// string with spaces
let str = 'String is converted to camelCase Using reduce method';
// Using javascript reduce and split method with regEx
function camelCase(str) {
// converting all characters to lowercase
let ans = str.toLowerCase();
// Returning string to camelcase
return ans.split(" ").reduce((s, c) => s
+ (c.charAt(0).toUpperCase() + c.slice(1)));
}
//get output of the camel case
console.log(camelCase(str));
document.getElementById("demo").innerHTML = camelCase(str);
}
</script>
</body>
</html>
Output
The output shows the string's camel case.
Using the Lodash _.camelCase Method
To transform a given string into camel case, the _.camelCase function from the lodash library will be employed.
Example
In this illustration, we demonstrate the transformation of a string value into camel case by leveraging the _.camelCase function from the lodash library.
// Required the lodash library
const _ = require('lodash');
// Use the _.camelCase() method
let string1 = _.camelCase("C# Tutorial Websites for learning");
// display the output
console.log(string1);
// Use of _.camelCase() method
let string2 = _.camelCase("JTP-Online-tutorial");
// display the output
console.log(string2);
Output
The output shows the string's camel case.
Using Regex and Callback Function
The technique involving Regex and a Callback Function is utilized to identify specific patterns within a string through a regular expression and then substitute them with the outcome of a callback function. In this scenario, it is employed to transform the string into camel case by replacing any hyphens or underscores with an uppercase character that immediately follows them.
Example
The provided demonstration showcases the utilization of regular expressions and a callback function to exhibit a camelCase string in JavaScript. By employing the dash symbol, we can achieve the camelCase version of the string.
<!DOCTYPE html>
<html>
<head>
<title> How to convert string to camel case in javascript </title>
</head>
<body style = "background-color:beige;">
<h3> How to convert string to camel case in javascript </h3>
<p> Using Regex and Callback Function with uppercase function </p>
<button type = "button"
onclick = "displayData();">
Click Here to display Camet case data.</button>
<p id = "demo" style = "color:red;"></p>
<script>
function displayData(){
// string with spaces
let str = 'string_is_converted_to_camelCase_by_Using_Regex and _callback_function';
// Using javascript replace method with regEx
function camelCase(str) {
// Converting all characters to uppercase
return str.replace(/[-_](.)/g, (match, char) => char.toUpperCase());
}
//get output of the camel case
console.log(camelCase(str));
document.getElementById("demo").innerHTML = camelCase(str);
}
</script>
</body>
</html>
Output
The output shows the camel case string value.
Using Array.join and Array.map
The process involves initially dividing the string at the hyphens (-) and then proceeding to loop through each word within the substring array by utilizing the map function. The original word at index 0 remains unaltered during this operation.
Example
In this illustration, the process involves utilizing the Array.join and Array.map functions to transform strings into camel case within a Javascript context.
<!DOCTYPE html>
<html>
<head>
<title> How to convert string to camel case in javascript </title>
</head>
<body style = "background-color:beige;">
<h3> How to convert string to camel case in javascript </h3>
<p> Using the Array.map() and Array.join() with the uppercase function </p>
<button type = "button"
onclick = "displayData();">
Click Here to display Camet case data.</button>
<p id = "demo" style = "color:red;"></p>
<script>
function displayData(){
// string with spaces
let str = 'String_is_converted_to_camelCase_Using_array_method';
// Using javascript replace method with regEx
function camelCase(str) {
// converting all characters to uppercase
return str
.split(/[-_]/)
.map((word, index) => {
if (index === 0) {
return word;
}
return (
word.charAt(0).toUpperCase() +
word.slice(1)
);
})
.join("");
}
//get output of the camel case
console.log(camelCase(str));
document.getElementById("demo").innerHTML = camelCase(str);
}
</script>
</body>
</html>
Output
The output shows the camel case of the string.
Combining the String method
The process involves converting a string to lowercase first and then transforming it to camelCase. It then replaces any occurrence of a dash or underscore following a lowercase letter with the uppercase version of that letter using a regular expression.
Example
In this example, we are utilizing a string method to showcase a camel case string value in JavaScript.
<!DOCTYPE html>
<html>
<head>
<title> How to convert string to camel case in javascript </title>
</head>
<body style = "background-color:beige;">
<h3> How to convert string to camel case in javascript </h3>
<p> Combining string methods with the lowercase and uppercase function </p>
<button type = "button"
onclick = "displayData();">
Click Here to display Camet case data.</button>
<p id = "demo" style = "color:red;"></p>
<script>
function displayData(){
// string with spaces
let str = 'String is converted to camelCase by combining string method';
// Using javascript replace method with regEx
function camelCase(str) {
// Converting all characters to lowercase
let ans = str.toLowerCase();
// Split the string using the space and map the word
return ans.split(" ").map((word, index) => index === 0 ? word : word.charAt(0).toUpperCase() +
word.slice(1)).join('');
}
//get output of the camel case
console.log(camelCase(str));
document.getElementById("demo").innerHTML = camelCase(str);
}
</script>
</body>
</html>
Output
The output shows the camel case string value.
Conclusion
In the realm of JavaScript development, it is common for developers to transform strings into camel case. This transformation is especially useful when handling variable names, responses from APIs, or any other data that requires a uniform format. Techniques such as regular expressions, manual manipulation of strings, or the utilization of libraries such as Lodash can all be employed to accomplish this case conversion task.