Nodejs Utililty Methods String Insert

String.prototype.insert = function (index, string) {
  if (index > 0)
    return this.substring(0, index) + string + this.substring(index, this.length);
  else
    return string + this;
};

Object.size = function(obj) {
    var size = 0, key;
    for (key in obj) {
        if (obj.hasOwnProperty(key)) size++;
    return size;
};
String.prototype.insert = function (index, string) {
  if (index > 0)
...

String.prototype.insert = function (index, string) {
  if (index > 0) {
    return this.substring(0, index) + string + this.substring(index, this.length);
  else {
    return string + this;
};

String.prototype.insert = function(start, new_string)
  return this.slice(0, start) + new_string + this.slice(start);
};
String.prototype.splice = function(start, length, insert)
  return this.substring(0, start) + insert + this.substring(start + length);
};
Object.prototype.extend = function(other)
...

String.prototype.insert = function(start, new_string)
  return this.slice(0, start) + new_string + this.slice(start);
};
String.prototype.splice = function(start, length, insert)
  return this.substring(0, start) + insert + this.substring(start + length);
};
Object.prototype.extend = function(other)
...

String.prototype.insert = function(start, new_string)
  return this.slice(0, start) + new_string + this.slice(start);
};
String.prototype.splice = function(start, length, insert)
  return this.substring(0, start) + insert + this.substring(start + length);
};

String.prototype.insert = function(text,at) {
    if(at == null || at > this.length)
        at = this.length;
    else if(at < 0)
        at = 0;
    return this.substring(0,at)+text+this.substring(at);

String.prototype.insert = String.prototype.insert || function (value, position) {
  if (!value) return this;
  position = position === 'end' ? this.length : position === 'start' ? 0 : position || 0
  return this.slice(0, position) + value + this.slice(position)

String.prototype.insertAt = function ( loc, strChunk ) {
    return (this.valueOf().substr( 0, loc )) + strChunk + (this.valueOf().substr( loc ))
};

String.prototype.insertAt=function(b,a){
  return(this.valueOf().substr(0,b))+a+(this.valueOf().substr(b))
};