question about recursion

Question

function a(num) {
if (num === 0) document.write(20);
document.write(num);
a(num - 1);
}
a(5);

so I have this code here that I thought the output would be 5432120 but instead, it goes forever. why?

Answer 1

You need to pack the bottom two lines into the `else` block, otherwise they will run regardless of whether you hit 0 or not!

Answer 2

There's no limit so the program will be running forever