Multiple conditions in While loop JS

Question

I don't really see how this could be wrong code.
In few examples, there is no output at all or it's only "10" in this one.

var num2 = 10;
while (num2 >= 10 && num2 <= 40 && num2%2===0){
    console.log(num2);
    num2++;
}

or like this:

var num2 = 10;
while (num2 >= 10 && num2 <= 40){
    if (num2%2===0){
    console.log(num2);
    num2++;
}}

What do you expect from this code? Try executing it step by step in a debugger — dee-see
– dee-see, Commented May 26, 2018 at 20:32

melpomene · Accepted Answer · 2018-05-26 20:37:03Z

3

Your first loop stops after the first iteration because 11 is not an even number, so num2%2===0 is false.

Your second loop never stops because it only increments num2 if it's even (from 10 to 11), but 11 is not even and so num2 never changes.

Fix:

var num2 = 10;
while (num2 >= 10 && num2 <= 40) {
    if (num2%2===0) {
        console.log(num2);
    }
    num2++;
}

I.e. always increment num2, but only print the even numbers.

Alternatively:

var num2 = 10;
while (num2 >= 10 && num2 <= 40) {
    console.log(num2);
    num2 += 2;
}

I.e. start at an even number and always increment by 2.

answered May 26, 2018 at 20:33

melpomene

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1 Comment

God, these devil curly brackets in wrong places :D Thanks