Nodejs Array Concatenate concatAll()

Method Source Code

/*/*from  w w w.ja  va 2s  .  c  o  m*/
   learned: forEach,
         map,
         filter 


   concatAll method flattens nested data structures so it's easier to access the info within them
*/


// here's a nested data structure - an array of an array;

var exchanges = [
  [
      { symbol: "XFX", price: 240.22, volume: 23432 },
      { symbol: "TNZ", price: 332.19, volume: 234 }
    ],
  [
      { symbol: "JXJ", price: 120.22, volume: 5323 },
      { symbol: "NYN", price: 88.47, volume: 98275 }
    ]
];

// run it on a nested array and creats a new array which contains the "flattened" results
Array.prototype.concatAll = function(){
   var results = [];

   this.forEach(function(subArray){
      subArray.forEach(function(item){
         results.push(item);
      });
   });   

   return results;
};

var stocks = exchanges.concatAll();

stocks.forEach(function(stock){
   console.log(JSON.stringify(stock));
});

/*
exchanges.forEach(function(exchange){
   exchange.forEach(function(stock){
      console.log(JSON.stringify(stock));
   });
});
*/

Related

1. concatAll()

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

2. concatAll()

   const exchanges= [
     [
       {symbol: 'XFX', price: 240.22, volume: 23432},
       {symbol: 'TNZ', price: 332.19, volume: 234},
     ],
     [
       {symbol: 'JXJ', price: 120.22, volume: 5323},
       {symbol: 'NYN', price: 88.47, volume: 98275},
     ],
   ...
   

3. concatAll()

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

4. concatAll()

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

5. concatAll()

   Array.prototype.concatAll = function() {
       this.forEach( function(val1) {
           val1.forEach( function (val2) {
                   return allWords.push(val2);
           });
       });
   };
   

6. concatAll()

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