New to JS. I'm trying to change my for loop to a while loop. It prints the factors of a number, but for some reason, the while loops causes the webpage to stop responding. Any help is appreciated.
var num, i = 1,
array = [];
num = parseInt(prompt("Please enter a number:"));
while (i < num) {
if (num % i == 0) {
array.push(i);
i++;
}
}
alert("The factors of " + num + " are: " + array + " and " + num);Move the incrementation of i variable outside the if condition. Else - the while loop will be stuck when the num is not divisible by specified i.
For example - if num is 5 and i is 2, the loop will be stuck because the if condition is not fulfilled - that's why i won't be incremented - and then we will experience an infinite loop.
var num, i = 1, array = [];
num = parseInt(prompt("Please enter a number:"));
while (i < num) {
if (num % i == 0) {
array.push(i);
}
i++;
}
alert("The factors of " + num + " are: " + array + " and " + num);
You increment i only if the condition of the "if" block is true. If that condition evaluates to false, i can't be incremented, and therefore the loop never ends.
if (num % i == 0) { // <some value except 0> % 1 == 0 -> false
array.push(i);
i++;
}
so try:
while (i < num) {
if (num % i == 0) {
array.push(i);
}
i++; // now i can be incremented regardless of the condition in the "if" block.
}
numa value if the prompt did not return a numeric value or not a value at all, you might end up withNaNwhich would also fall into the case ofi < numreturningfalse