How to subtract one array from another, element-wise, in javascript

user_1686660 0
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If i have an array A = [1, 4, 3, 2] and B = [0, 2, 1, 2] I want to return a new array (A - B) with values [1, 2, 2, 0]. What is the most efficient approach to do this in javascript?

javascript
6 Answers

const A = [1, 4, 3, 2]
const B = [0, 2, 1, 2]
console.log(A.filter(n => !B.includes(n)))

user_17387770 
const A = [1, 4, 3, 2]
const B = [0, 2, 1, 2]
const C = A.map((valueA, indexInA) => valueA - B[indexInA])
console.log(C) // [1, 2, 2, 0]

Here the map is returning the substraction operation for each number of the first array.

Note: this will not work if the arrays have different lengths

user_119737940

One-liner using ES6 for the array's of equal size in length:

 let subResult = a.map((v, i) => v - b[i]); // [1, 2, 2, 0]

v = value, i = index

user_13085890
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