查找二维数组JavaScript的转置
我们需要编写一个JavaScript函数，该函数接受一个二维数组并返回其转置数组。
为此的代码将是-
方法1：使用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));方法2：使用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));两种方法在控制台中的输出将是-
[ [ 0, 2, 4 ], [ 1, 3, 5 ] ]