I am trying to learn how to pare two values between arrays with corresponding index. Like

var A = [2,12,3,42];
var B = [12,42,44,12];

So i know i need to loop in these arrays, but how do i pare two values based on index?

Like, index of [0] from A to pare with index of [0] from B, etc?

I am trying to learn how to pare two values between arrays with corresponding index. Like

var A = [2,12,3,42];
var B = [12,42,44,12];

So i know i need to loop in these arrays, but how do i pare two values based on index?

Like, index of [0] from A to pare with index of [0] from B, etc?

• javascript
• arrays

• 2 Possible duplicate of How to pare arrays in JavaScript? – Rajesh Commented Oct 22, 2016 at 14:15

2 Answers 2

You will have to loop over arrays and pare every element.

Considering, there can be arrays of different length, you should take max of them and check. Under such circumstances, if length of A is 4 and you try to access A[4] this will return undefined.

var A = [2, 12, 3, 42];
var B = [12, 42, 44, 12, 123];

var len = Math.max(A.length, B.length);
console.log(len)
for (var i = 0; i < len; i++) {
  console.log(A[i], B[i], A[i] === B[i])
}

var firstElementEqual = A[0] === B[0]

This should be everything you need to do. You can simply reference the values by using the index and then paring it like it's a normal variable.

Example:

var A = [2,12,3,42];
var B = [12,42,44,12];

console.log(A[0] === B[0]); // This will return false, as 2 A[0] is not equal to 12 B[0]