Javascript String startsWith(prefix)

String.prototype.startsWith = function(prefix){
  if(prefix.length > this.length)
    return false;
  
  for(var i = 0; i < prefix.length; i++)
    if(prefix[i] != this[i])
      return false;
  
  return true;//from   ww w .  jav  a  2  s . co  m
}

String.prototype.startsWith = function (prefix) {
    return this.indexOf(prefix) === 0;
}

String.prototype.endsWith = function (suffix) {
    return this.match(suffix + "$") == suffix;
};

String.prototype.startsWith = function(prefix){
    return !this.indexOf(prefix);
};

String.prototype.startsWith = function (prefix) {
 "use strict";//from  w w w . j  av  a  2  s. c o  m

 if (!prefix && typeof prefix !== 'string') {
  return false;
 }

 return this.indexOf(prefix) === 0;
};

String.prototype.startsWith = function(prefix) {
    return (this.substr(0, prefix.length) === prefix);
};

/**//  w ww.  ja v  a 2s  . c o  m
 * see if a string begins with a given string
 * 
 * Once ecmascript adds this natively, you should build core.js without this method:
 * @link http://wiki.ecmascript.org/doku.php?id=harmony%3astring_extras
 * @function external:String.prototype.startsWith
 * @param {string} A substring expected to be in the beginning of this string
 * @return {boolean}
  * @example
  *  'some string'.startsWith('s') === true;
 */
String.prototype.startsWith = function (prefix){
    return this.slice(0, prefix.length) === prefix;
};

/**/*from   w w  w  . jav a  2 s .  c  o m*/
 * see if a string begins with a given string
 * 
 * Once ecmascript adds this natively, you should build core.js without this method:
 * @see {@link http://wiki.ecmascript.org/doku.php?id=harmony%3astring_extras Harmony String Extras}
 * @function module:String.prototype.startsWith
 * @param {string} A substring expected to be in the beginning of this string
 * @return {boolean}
  * @example
  *  'some string'.startsWith('s') === true;
 */
String.prototype.startsWith = String.prototype.startsWith || function (prefix){
    return this.slice(0, prefix.length) === prefix;
};

var DBG = false;// w  ww .  j  a  v  a 2s .  c om

String.prototype.startsWith = function(prefix) {
    return this.indexOf(prefix) === 0;
}

String.prototype.endsWith = function(suffix) {
    return this.match(suffix+"$") == suffix;
};