What is the best way to traverse an array without going beyond its limits?

Question

JavaScript

I'm asking for help in finding the best option for this situation.
There is a certain section of "spherical code in a vacuum":

var Arr = [][];
Arr.length = 100;

for(var i=0; i<100; i++) {
    for(var j=0; j<100; j++) {
        if(Arr[i + 10][j + 10] === 1) {
            // что-то произойдёт
        }
    }
}

Given a two-dimensional array of 100 x 100, when trying to substitute a condition without checking the length, which clearly exceeds the array limit, for example: Arr[i+10][j+10] - we get the corresponding error “cannot read property of undefined”. Maybe there is some other way to avoid piling up checks before the necessary condition?

Answer 1

Why "heaps"? You just need to check if there is:
In general, you can set this 100 (it doesn’t come from nowhere?) via:
var s = Math.min(100, Arr.length);

Answer 2

Or add functionality using the forEach method . There are indexes and everything else. Well, if you access an array element, no one will check for its existence for you.

Answer 3

the array must have a length property. And if you don’t need indexes i, j to death, then try using foreach loops