Question

How to clone a two-dimensional array in Node.js

Answer 1

let arr2D = [
    [1, 2, 3, 0, 101],
    [4, 5, 6, 17, 892],
    [7, 8, 9, 28, 903]
];
  
let clonedArray = arr2D.map(innerArray => innerArray.slice());
  
console.log(clonedArray);
  
  
  
/*
run:
  
[ [ 1, 2, 3, 0, 101 ], [ 4, 5, 6, 17, 892 ], [ 7, 8, 9, 28, 903 ] ]
  
*/

 

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Answer 2

let arr2D = [
    [1, 2, 3, 0, 101],
    [4, 5, 6, 17, 892],
    [7, 8, 9, 28, 903]
];
  
let clonedArray = JSON.parse(JSON.stringify(arr2D));
  
console.log(clonedArray);
  
  
  
/*
run:
  
[ [ 1, 2, 3, 0, 101 ], [ 4, 5, 6, 17, 892 ], [ 7, 8, 9, 28, 903 ] ]
  
*/

 

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Answer 3

let arr2D = [
    [1, 2, 3, 0, 101],
    [4, 5, 6, 17, 892],
    [7, 8, 9, 28, 903]
];
  
let clonedArray = [];
let arr2D_length = arr2D.length;
for (let i = 0; i < arr2D_length; i++) {
    clonedArray[i] = [];
    let arr2D_i_length = arr2D[i].length;
    for (let j = 0; j < arr2D_i_length; j++) {
        clonedArray[i][j] = arr2D[i][j];
    }
}
  
console.log(clonedArray);
  
  
  
/*
run:
  
[ [ 1, 2, 3, 0, 101 ], [ 4, 5, 6, 17, 892 ], [ 7, 8, 9, 28, 903 ] ]
  
*/

 

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