Syntax error Converting any case to camelCase in JavaScript

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

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
Revathi Satya Kondra
Revathi Satya Kondra

Technical Content Writer, Tutorialspoint

Updated on: 2025-01-30T17:47:41+05:30

869 Views

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