Question

How to concatenate two arrays in JavaScript

Answer 1

var arr_s = ['a', 'b', 'c'],
    arr_n = [1, 2, 3];

var arr = arr_s.concat(arr_n);

for (i = 0; i < arr.length; i++)
  document.write("arr[" + i + "] = " + arr[i] + "<br />"); 

/*
run:  

arr[0] = a
arr[1] = b
arr[2] = c
arr[3] = 1
arr[4] = 2
arr[5] = 3

*/

 

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Answer 2

var arr1 = [1, 2, 3];
var arr2 = [4, 5, 6, 7];

var arr3 = arr1.concat(arr2); 

document.write(arr3);

/*
run:
  
1,2,3,4,5,6,7
  
*/

 

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Answer 3

var arr1 = [1, 2, 3];
var arr2 = [4, 5, 6, 7];
 
arr1.push.apply(arr1, arr2);
 
document.write(arr1);

/*
run:
  
a,b,c,d,e,f,g,h,i,j
  
*/

 

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