Question

How to create a two dimensional (2D) array in JavaScript

Answer 1

const rows = 3;
const cols = 2;

let arr = new Array(rows); 

for (var i = 0; i < rows; i++) {
    arr[i] = new Array(cols);
}

console.log(arr); 

  
  
    
    
/*
run:
    
[[undefined, undefined], [undefined, undefined], [undefined, undefined]]
    
*/

 

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Answer 2

const rows = 3;
const cols = 2;

let arr = Array.from(Array(rows), () => new Array(cols));

console.log(arr); 

  
  
    
    
/*
run:
    
[[undefined, undefined], [undefined, undefined], [undefined, undefined]]
    
*/

 

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Answer 3

const rows = 3;
const cols = 2;

let arr = Array(rows).fill().map(() => Array(cols));

console.log(arr); 

  
  
    
    
/*
run:
    
[[undefined, undefined], [undefined, undefined], [undefined, undefined]]
    
*/

 

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Answer 4

const rows = 3;
const cols = 4;
const arr = new Array(rows).fill(new Array(cols).fill(0));
 
console.log(arr);
 
 
 
 
/*
run:
 
[ [ 0, 0, 0, 0 ], [ 0, 0, 0, 0 ], [ 0, 0, 0, 0 ] ]
 
*/

 

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Answer 5

const arr = [[5, 2],
             [9, 8],
             [1, 4]];
  
console.log(arr[0][0]); // 5
console.log(arr[0][1]); // 2
console.log(arr[1][0]); // 9
console.log(arr[1][1]); // 8
console.log(arr[2][0]); // 1
console.log(arr[2][1]); // 4
  
console.log(arr);
  
     
     
     
/*
run:
     
5
2
9
8
1
4
[ [ 5, 2 ], [ 9, 8 ], [ 1, 4 ] ]
  
*/

 

70+ SQL courses for beginners and professionals