Nodejs Array Map map(testFunction)

Method Source Code

Array.prototype.map = function(testFunction){
   var result = [];
   this.forEach(function(item){
      result.push(testFunction(item));//  ww w. j a  v a  2s. c o m
   })
   return result;
}

Related

1. map(projectionFunction)

   Array.prototype.map = function(projectionFunction) {
     var results = [];
     this.forEach(function(itemInArray) {
       results.push(projectionFunction(itemInArray));
     });
     return results;
   };
   

2. map(projectionFunction)

   Array.prototype.map = function(projectionFunction) {
     var results = [];
     this.forEach(function(itemInArray) {
       results.push(projectionFunction(itemInArray));
     });
     return results;
   };
    var answer = JSON.stringify([1,2,3].map(function(x) { return x + 1; })) === '[2,3,4]';
    console.log(answer);
   ...
   

3. map(projectionFunction)

   Array.prototype.map = function(projectionFunction) {
     var results = [];
     this.forEach(itemInArray => results.push(projectionFunction(itemInArray)) );
     return results;
   };
   

4. map(projectionFunction)

   Array.prototype.map = function (projectionFunction) {
     var results = [];
     this.forEach(function (itemInArray) {
       results.push(projectionFunction(itemInArray));
     });
     return results;
   };
   

5. map(projectionFunction)

   Array.prototype.map = function(projectionFunction) {
     var results = [];
     this.forEach(function(itemInArray) {
     });
     return results;
   };
   JSON.stringify(
     [1,2,3].map(function(x) {
       return x + 1;
   ...
   

6. map(transform)

   Array.prototype.map = function (transform) {
     let mappedArray = [];
     const len = this.length;
     for (let i = 0; i < len; i += 1) {
       mappedArray.push(transform(this[i], i, this));
     return mappedArray;
   };
   

7. map(transformer)

   Array.prototype.map = function(transformer) {
     var result = []
     for ( var i = 0; i < this.length; i++) {
       result.push(transformer(this[i]));
     return result;
   

8. map2(projection)

   const stocks= [
     {symbol: 'XFX', price: 240.22, volume: 23432},
     {symbol: 'TNZ', price: 332.19, volume: 234},
     {symbol: 'JXJ', price: 120.22, volume: 5323},
   ]
   Array.prototype.map2= function(projection) {
     let results= []
     this.forEach(item => results.push(projection(item)))
     return results
   ...
   

9. mapByTwo(fun /*, thisp*/)

   Array.prototype.mapByTwo = function(fun ) {
     if (typeof fun != "function")
       throw new TypeError();
     var len = this.length >>> 0;
     var thisp = arguments[1];
     var k = 0;
     var A = new Array(Math.ceil(len/2));
     if (len/2 < A.length) {
       this.push(null);
   ...