30-seconds-of-code/snippets/fromCamelCase.md

title, tags

title	tags
fromCamelCase	string,intermediate

Converts a string from camelcase.

• Use String.prototype.replace() to break the string into words and add a separator between them.
• Omit the second argument to use a default separator of _.

const fromCamelCase = (str, separator = '_') =>
  str
    .replace(/([a-z\d])([A-Z])/g, '$1' + separator + '$2')
    .replace(/([A-Z]+)([A-Z][a-z\d]+)/g, '$1' + separator + '$2')
    .toLowerCase();

fromCamelCase('someDatabaseFieldName', ' '); // 'some database field name'
fromCamelCase('someLabelThatNeedsToBeDecamelized', '-'); // 'some-label-that-needs-to-be-decamelized'
fromCamelCase('someJavascriptProperty', '_'); // 'some_javascript_property'