avascript loop last index code example

Example 1: js detect end of array

var group = ["a","b","c","d"];
var groupLength = group.length;

while (groupLength--) {
    var item = group[groupLength];

    if(groupLength == 0){
        console.log("Last iteration with item : " + item);
    }
}

Example 2: javascript loop last index

for (const [i, value] of arr.entries()) {
    if (i === arr.length - 1) {
        // do your thing
    }
}