Question

How to transpose a matrix (swap rows and columns) in JavaScript

Answer 1

function print(matrix) {
    const rows = matrix.length;
    const cols = matrix[0].length;
    
    for (let i = 0; i < rows; i++) {
        let s = "";
        for (let j = 0; j < cols; j++) {
             s += matrix[i][j] + " ";
        }
        console.log(s);
    }
}
  
function transpose(matrix) {
    return matrix[0].map((col, i) => matrix.map(row => row[i]));
}
   
let matrix = [ [1, 2, 3, 5],
               [4, 5, 6, 1],
               [7, 8, 9, 0] ];
  
matrix = transpose(matrix); 
  
print(matrix);

       
       
/*
run:
       
1 4 7 
2 5 8 
3 6 9 
5 1 0 
       
*/

 

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