Duplicate an array an arbitrary number of times (javascript)

Question

Let\'s say I\'m given an array. The length of this array is 3, and has 3 elements:

var array = [\'1\',\'2\',\'3\'];

Eventually I will need

Answer 1

You can do:

var array = ['1','2','3'];


function nplicate(times, array){
      //Times = 2, then concat 1 time to duplicate. Times = 3, then concat 2 times for duplicate. Etc.
     times = times -1;
     var result = array;

    while(times > 0){
        result = result.concat(array);
        times--;
    }

    return result;
}

console.log(nplicate(2,array));

You concat the same array n times.

Use concat function and some logic: http://www.w3schools.com/jsref/jsref_concat_array.asp

Answer 2

Basic but worked for me.

var num = 2;

while(num>0){
array = array.concat(array);
num--}

Answer 3

if you are inside a loop you can verify the current loop index with the array length and then multiply it's content.

let arr = [1, 2, 3];

if(currentIndex > arr.length){ 
  //if your using a loop, make sure to keep arr at a level that it won't reset each loop

  arr.push(...arr);

}

Full Example: https://jsfiddle.net/5k28yq0L/