Javascript String endsWith(searchString)

String.prototype.endsWith = function(searchString) {
var result = true;     
  var subjectString = this.toString();
  for(var i=1;i<=searchString.length;i++){
   var lastcharsubjectString = subjectString.charAt(subjectString.length-i);
   console.log("lastcharsubjectString   ---- >> "+lastcharsubjectString);
   var lastcharsearchString =searchString.charAt(searchString.length-i);
   console.log("lastcharsearchString   ---- >> "+lastcharsearchString);
  if(lastcharsubjectString != lastcharsearchString){
   result = false;/*w w  w . ja  va  2 s . com*/
   break;
  }
 }
    alert(result);  
      
  };
 "gridSelected-123".endsWith("123");