Nodejs Array Concatenate concat()

Method Source Code

Array.prototype.concat = function(){
   var result = [];
   this.forEach(function(subArray){
      result.push.apply(result, subArray);
   });/*from  w ww  . j  av  a 2  s .  c  o  m*/
   return result;
}

var a = [[2,3,4,5],[11,2,333],[33,232,21]];
a.concat();


var a = [1,22,34,4,66];
Math.max.apply(null,a); // works beacuse it gives it as a[0],a[1] etc
but Math.max.call(null,a) // NaN. Because call cannot split it as a[0],a[1], hence a is intrepreted as whoe array and Not a Number

Related

1. concat(ar)

   Array.prototype.concat = function(ar) {
     var results = new Array(this.length + ar.length);
     for (var i = 0, len = this.length; i < len; i++) {
       results[i] = this[i];
     for (var i = 0, len = ar.length; i < len; i++) {
       results[len + i] = ar[i];
     return results;
   ...
   

2. concat(arg)

   var my_array=Array.prototype.concat;
   Array.prototype.concat=function (arg) {
       var result = arg[0];
       for (var i = 1; i < arg.length; i++) {
           result += "-" + arg[i];
       console.log(result);
   var piyo=new Array(100,200,300);
   ...
   

3. concatAll()

   Array.prototype.concatAll = function() {
     var results = [];
     this.forEach(function(subArray) {
       results.push.apply(results, subArray);
     });
     return results;
   };
   

4. concatAll()

   Array.prototype.concatAll = function() {
     var results = [];
     this.forEach(function(subArray) {
       subArray.forEach(function(item) {
         results.concat(item);
       });
     });
     return results;