map 子阵列在 javascript 中具有新值

Question

I have an array, array = [[1,2,3], [4,5,6]] .

I need a new array with the value [[1,2,3], [8,10,12]]

I tried array[1].map((el) => el*2) , but it's not return the array which I want.

Please help me out to solve this issue.

Answer 1

You might use a nested map, multiply by the index of the outer map you're on (plus one).

 const arr = [[1,2,3], [4,5,6]]; const result = arr.map((subarr, i) => subarr.map(val => val * (i + 1)) ); console.log(result);