function makeRandomCharArr()
{
    var text = "";
    var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
    var size = getRandomNumber(1, 15);

    for( var i=0; i < size; i++ )
        text += possible.charAt(Math.floor(Math.random() * possible.length));

    return text.split('');
}

function getRandomNumber(min, max) {
    return Math.floor(Math.random() * (max - min) + min);
}

function compareLengths(a, b) {
    if (a > b) {
        return b;
    } else {
        return a;
    }
}

var arr1 = makeRandomCharArr();
var arr2 = makeRandomCharArr();

console.log(arr1);
console.log(arr2);

for (var i = 0; i <= compareLengths(arr1.length, arr2.length); i += 1) {
    if (arr1[i] > arr2[i]){
        console.log('first is: ' + arr2);
        break;
    } else {
        console.log('first is: ' + arr1);
        break;
    }
    if (arr1.length > arr2.length) {
        if (i === arr2.length - 1) {
            console.log('first is: ' + arr2)
            break;
        }
    } else if (arr1.length < arr2.length) {
        if (i === arr1.length - 1) {
            console.log('first is: ' + arr1)
        }
    }
}