Converting any case to camelCase in JavaScript

In this article, we create a function that can take a string in any format. Such as normal case, snake case, pascal case or any other into camelCase in JavaScript.

camelCase is a writing style where each word within a phrase is capitalized, except for the first word, and there are no spaces or punctuation.

Let us understand through some sample example of I/O Scenario ?

Sample Input -

const str = 'New STRING';

Sample Output -

const output = 'newString'; 

Converting any case to camelCase in JavaScript

Converting any case to camelCase in JavaScript is quite easy. Let's learn through the following programs ?

• Using Regular Expressions
• Splitting and Mapping
• Using String Manipulation and Iteration

Using Regular Expressions

In this program, the function toCamelCase(str) converts a given string to camelCase format by lowercase and then replace any non-alphanumeric characters followed by a character with just that character in uppercase, applying it to 'snakeCase', 'kebabCase', and 'mixedCase'.

Example

function toCamelCase(str) { return str .toLowerCase() .replace(/[^a-zA-Z0-9]+(.)/g, (match, group1) => group1.toUpperCase()); } const snakeCase = "tutorials_point"; const kebabCase = "tutorials-point"; const mixedCase = "Tutorials-Point_Company"; console.log(toCamelCase(snakeCase)); console.log(toCamelCase(kebabCase)); console.log(toCamelCase(mixedCase)); 

Output

The above program produce the following result ?

tutorialsPoint tutorialsPoint tutorialsPointCompany 

Using Splitting and Mapping

Here, The function 'toCamelCase(str)' converts a string to camelCase by splitting it based on non-alphanumeric characters, lowercasing the first word, and capitalizing the first letter of subsequent words. Then it joins these words back into a single string.

Note: In pascel case it convert all the string into lowercase because the entire string is treated as a single word.

Example

function toCamelCase(str) { const words = str.split(/[^a-zA-Z0-9]+/).map((word, index) => { if (index === 0) return word.toLowerCase(); return word.charAt(0).toUpperCase() + word.slice(1).toLowerCase(); }); return words.join(''); } const normalCase = "Tutorials company"; const snakeCase = "tutorials_point_company"; const pascalCase = "TutorialsPointCompany"; console.log(toCamelCase(normalCase)); console.log(toCamelCase(snakeCase)); console.log(toCamelCase(pascalCase)); 

Output

Following is the output of the above program ?

tutorialsCompany tutorialsPointCompany tutorialspointcompany 

Using String Manipulation and Iteration

In the following program, the function 'toCamelCase(str)' iterates through each character of the string, converting it to lowercase and setting a flag to capitalize the next character when encountering non-alphanumeric characters. This creates camelCase from strings with separators.

Example

function toCamelCase(str) { let result = ''; let capitalizeNext = false; for (let i = 0; i < str.length; i++) { const char = str[i]; if (/[^a-zA-Z0-9]/.test(char)) { capitalizeNext = true; } else { if (capitalizeNext) { result += char.toUpperCase(); capitalizeNext = false; } else { result += char.toLowerCase(); } } } return result; } const kebabCase = "tutorials-point-company"; const mixedCase = "Tutorials Point_Company"; console.log(toCamelCase(kebabCase)); console.log(toCamelCase(mixedCase)); 

Output

Following is the output of the above program ?

tutorialsPointCompany tutorialsPointCompany