Camelcase string

JavaScript, String, Regexp · Oct 22, 2020

Converts a string to camelcase.

Use String.prototype.match() to break the string into words using an appropriate regexp.
Use Array.prototype.map(), Array.prototype.slice(), Array.prototype.join(), String.prototype.toLowerCase() and String.prototype.toUpperCase() to combine them, capitalizing the first letter of each one.

const toCamelCase = str => {
  const s =
    str &&
    str
      .match(
        /[A-Z]{2,}(?=[A-Z][a-z]+[0-9]*|\b)|[A-Z]?[a-z]+[0-9]*|[A-Z]|[0-9]+/g
      )
      .map(x => x.slice(0, 1).toUpperCase() + x.slice(1).toLowerCase())
      .join('');
  return s.slice(0, 1).toLowerCase() + s.slice(1);
};

toCamelCase('some_database_field_name'); // 'someDatabaseFieldName'
toCamelCase('Some label that needs to be camelized');
// 'someLabelThatNeedsToBeCamelized'
toCamelCase('some-javascript-property'); // 'someJavascriptProperty'
toCamelCase('some-mixed_string with spaces_underscores-and-hyphens');
// 'someMixedStringWithSpacesUnderscoresAndHyphens'