How to find a first occurrence of double digit number

Question

So, I am pushing elements into array through prompt until getting 0. After that I am trying to find the first double digit number. For example if the array is [2,3,55,0] my program should return 55.

function findFirstDouble() {
	var niz = []
	var a = 1;
	for (var i = 1; a != 0; i++) {
		var unos = parseInt(prompt("Enter number :"))
		niz.push(unos)
		a = unos
	}
	alert(niz);
	for (var i = 0; i < niz.length; i++) {
		if (niz[i] / 10 > 0 && niz[i] / 100 == 0) {
			console.log(niz[i]); 
			break;
		}
		else {
			alert("No double digit numbers!")
			break;
		}
	}
}
findFirstDouble();

Answer 1

Here is the answer I think you are looking for.

I omitted the array filling part.

Why would you do any kind of division if you just need to check every number and if the first one matches the criteria then you've got your double digit number hence exit the loop with break or return keyword.

var niz = [1, 2, 55, 13];
for (var i = 0; i < niz.length; i++) {
    if (niz[i] > 9 && niz[i] < 100) {
        console.log('Pronadeni broj je:', niz[i]);
        break;
    }
}

You can also convert to string: if (niz[i].toString().length===2){ // your number }