Nodejs Object Key Get contains(key)

Method Source Code

// Additions to the Object prototype

Object.prototype.contains = function (key) {
    return this.hasOwnProperty(key);
};

Related

1. keys()

   Object.prototype.keys = function() {
       var keys = [];
       $.each(this, function(key, value) {
           keys.push(key);
       });
       return keys;
   };
   

2. keys_length()

   Object.defineProperty(Object.prototype, 'keys_length', {
       enumerable:false,
       value:function() {
           var size = 0, key;
           for (key in this) {
               if (this.hasOwnProperty(key)) size++;
           return size;
   })
   

3. getKeys()

   Object.prototype.getKeys = function(){
     var keys = [];
     for (var key in this) {
       if (this.hasOwnProperty(key)) {
         keys.push(key);
     return keys
   

4. getOwn(key, defaultValue)

   Object.prototype.getOwn = function(key, defaultValue) {
       if (this.hasOwnProperty(key)) {
     return this[key];
       else {
     return defaultValue;
   };
   

5. hasKey(skey)

   Object.prototype.hasKey = function(skey){
     for (var key in this) {
       if (this.hasOwnProperty(key)) {
         if(key==skey){
           return true
     return false
   ...
   

6. empty()

   Object.prototype.empty = function() {
     return Object.keys(this).length <= 0;
   

7. isEmpty()

   Object.prototype.isEmpty = function() {
       if (this == null) return true;
       if (this.length > 0)    return false;
       if (this.length === 0)  return true;
       for (var key in this) {
           if (hasOwnProperty.call(this, key)) return false;
       return true;
   };
   ...