We are required to write a JavaScript function that takes in a two-dimensional array and returns its transposed array.
The code for this will be −
Method 1: Using Array.prototype.forEach()
const arr = [
[0, 1],
[2, 3],
[4, 5]
];
const transpose = arr => {
const res = [];
arr.forEach((el, ind) => {
el.forEach((elm, index) => {
res[index] = res[index] || [];
res[index][ind] = elm;
});
});
return res;
};
console.log(transpose(arr));Method 2: Using Array.prototype.reduce()
const arr = [
[0, 1],
[2, 3],
[4, 5]
];
const transpose = arr => {
let res = [];
res = arr.reduce((acc, val, ind) => {
val.forEach((el, index) => {
acc[index] = acc[index] || [];
acc[index][ind] = el;
});
return acc;
}, [])
return res;
};
console.log(transpose(arr));The output in the console for both the methods will be −
[ [ 0, 2, 4 ], [ 1, 3, 5 ] ]