phpjs/functions/strings/strchr.js

php.js offers community built php functions in javascript

function strchr(haystack, needle, bool) {
  // From: http://phpjs.org/functions
  // +   original by: Philip Peterson
  // -    depends on: strstr
  // *     example 1: strchr('Kevin van Zonneveld', 'van');
  // *     returns 1: 'van Zonneveld'
  // *     example 2: strchr('Kevin van Zonneveld', 'van', true);
  // *     returns 2: 'Kevin '
  return this.strstr(haystack, needle, bool);
}