Nodejs Array Map map(callback)

Here you can find the source of map(callback)

Method Source Code

Array.prototype.map = function(callback) {
  var result = [];
  for(var i = 0; i < this.length; i += 1) {
    result.push(callback.call(this[i]));
  }/* ww w .  j a  va  2s .c o m*/
  return result;
};

Related

  1. map( func /*, obj */)
    Array.prototype.map = function(  func ) {
      var len = this.length;
      if (typeof func != 'function') {
        throw new Error("argument must be function");
      };
      var res = [];
      var obj = arguments[1];
      console.log("obj" + obj)
      for (var i = 0; i < len; i++) {
    ...
    
  2. map( fn )
    Array.prototype.map = function( fn )
        var a = [];
        for( var i = 0; i < this.length; i++ ) {
            if( i in this ) a.push( fn( this[ i ] ) );
        return a;
    };
    
  3. map(a)
    Array.prototype.map = function(a) {
      const array = new Array(this.length)
      for (let i = 0; i < this.length; i++) array[i] = a(this[i], i, this)
      return array
    
  4. map(callback)
    Array.prototype.map = function (callback) {
        var obj = this;
        var value, mapped_value;
        var A = new Array(obj.length);
        for (var i = 0; i < obj.length; i++) {
            value = obj[i];
            mapped_value = callback.call(null, value);
            A[i] = mapped_value;
        return A;
    };
    var arr = [1, 2, 3];
    var new_arr = arr.map(function (value) {
        return value * value;
    });
    console.log(new_arr);
    
  5. map(callback)
    Array.prototype.map = function(callback) {
      let res = [];
      this.forEach(el => res.push(callback(el)));
      return res;
    };
    let a = [1,2,3];
    let b = a.map(el => el * el);
    console.log(a);
    console.log(b);
    ...
    
  6. map(callback)
    Array.prototype.map = function(callback){
      var a = 0,
        len = this.length,
        result = [];
      while(a < len){
        result.push(callback(this[a], a++, this));
      return result;
    };
    ...
    
  7. map(callback)
    Array.prototype.map = function(callback){
        const newArr = []
        for(let i = 0; i < this.length; i += 1){
            let newValue = callback(this[i])
            newArr.push(newValue)
        return newArr
    var someArray = [1,2,3,4]
    ...