Nodejs Array Select select(projection)

Method Source Code

Array.prototype.select = function (projection) {
    var results = [];
    for (var i = 0; i < this.length; i++) {
        results.push(projection(this[i]));
    }//from  w ww .  ja  v a 2  s  . c  o m
    return results;
};

var children = [{ id: 1, Name: "Rob" }, { id: 2, Name: "Sansa" }, { id: 3, Name: "Arya" }, { id: 4, Name: "Brandon" }, { id: 5, Name: "Rickon" }];
var filteredChildren = children.where(function (x) {
    return x.id % 2 == 0;
}).select(function (x) {
    return x.Name;
});
console.dir(children);
console.dir(filteredChildren);

Related

1. select(fnCallback)

   Array.prototype.select = function(fnCallback) {
       var value = Array();
       for (var elementIndex in this) {
           if (this.hasOwnProperty(elementIndex)) {
               value.push(fnCallback.apply(this[elementIndex], [elementIndex]));
       return value;
   };
   ...
   

2. select(fun)

   Array.prototype.select = function(fun) {
     return this.reduce(function(res, el) {
       if(fun(el)) {
         res.push(el);
       };
       return res;
     }, []);
   

3. select(func)

   Array.prototype.select = function (func) {
       var length = this.length,
           items = [];
       for (var i = 0; i < length; i++) {
           items.push(func(this[i]));
       return items;
   

4. select(lambda)

   Array.prototype.select = function(lambda) {
       if (lambda == undefined) {
           return this;
       } else {
           result = [];
           for (i = 0; i < this.length; i++) {
               if (lambda(this[i])) {
                   result.push(this[i]);
           return result;
   };
   

5. select(predicate)

   Array.prototype.select = function(predicate){
       var r = []
       for(var n = 0; n < this.length; n++) {
           if(predicate(this[n])){
               r.push(this[n]);
       return r;
   };
   ...
   

6. select(selectFunction)

   Array.prototype.select = function(selectFunction) {
       return this.inject([], function(result, element) {
           if (selectFunction(element)) {
               result.push(element);    
           return result;
       });
   };
   

7. select(selector)

   Array.prototype.select = function (selector) {
       if (selector == null || typeof (selector) !== 'function') throw new Error('selector should');
       var result = [];
       for (var i = 0; i < this.length; i++) {
           result.push(selector(this[i]));
       return result;
   };
   

8. select(selector, context)

   Array.prototype.select = Array.prototype.map || function (selector, context) {
     context = context || window;
     var arr = [];
     var l = this.length;
     for (var i = 0; i < l; i++)
       arr.push(selector.call(context, this[i], i, this));
     return arr;
   };
   

9. select(transformer)

   Array.prototype.select = function(transformer) {
       if (typeof(transformer) != "function") {
           throw new Error("The argument must be a function");
       var arr = [];
       for (var i = this.length - 1; i >= 0; i--) {
           arr[i] = transformer(this[i]);
       return arr;
   ...