Nodejs Array Select selectMany(fn)

Method Source Code

let src = [//from   w  w w.j  av a  2s.  c om
    [1, 2, 3, 4],
    [2, 7, 8, 9],
    [1, 2, 3, 4],
];

let src1 = [1, 123, 567];

Array.prototype.selectMany = function(fn) {

    let resultArray = [];
    let result = [];

    for(let i = 0; i < this.length; i++) {
        resultArray = resultArray.concat(this[i]);
    }

    for(let n = 0; n < resultArray.length; n++) {
        
        let string = fn(resultArray[n]);

        if(typeof(string) === "string") {
            for(let s = 0; s < string.length; s++) {
                result.push(Number(string[s]))
            }
        } else {
            result.push(string)
        }

    }

    return result;
}


console.log(src.selectMany(function(x){ return x;}));
console.log(src1.selectMany(function(x){ return x + 2;}));
console.log(src1.selectMany(function(x){ return x + "";}));
console.log(src1.selectMany(function(x){ return x > 10;}));

Related

1. select(projection)

   Array.prototype.select = function (projection) {
       var results = [];
       for (var i = 0; i < this.length; i++) {
           results.push(projection(this[i]));
       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) {
   ...
   

2. select(selectFunction)

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

3. 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;
   };
   

4. 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;
   };
   

5. 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;
   ...
   

6. selectMany(selector, resSelector)

   Array.prototype.selectMany = function (selector, resSelector) {
     resSelector = resSelector || function (i, res) { return res; };
     return this.aggregate(function (a, b) {
       return a.concat(selector(b).select(function (res) { return resSelector(b, res) }));
     }, []);
   };
   

7. selectObjects(key, array)

   Array.prototype.selectObjects = function(key, array){
     var toReturn = []
     $.each(this, function(i, object){
       if(array.indexOf(object[key]) > -1){
         toReturn.push(object)
     })
     return toReturn
   

8. selectOne(filter)

   Array.prototype.selectOne = function(filter)
     for (var i = 0; i< this.length; i++) {
       if(filter(this[i])){
         return this[i];
     return null;
   

9. selectRandom()

   var alphabet = "aabcdeefghiijklmnoopqrstuuvwxyyz";
   function randint(min, max) {
       return Math.floor(Math.random() * (max - min)) + min;
   Array.prototype.selectRandom = function() {
       return this[randint(0, this.length)];
   };
   function random_word(min, max) {
       var word = "";
   ...