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javascriptrecursionmathfactorialcallstack

factorial of a negative number exceeds maximum call stack size

Why is the maximum call stack size exceeded when attempting to apply this simple factorial function to a negative number? 

function factorial(n) { 
    if (n == 0) { 
        return 1 
    }

    return n * factorial(n - 1) 
}

I understand that factorial functions are meant for non-negative integers, but I'm wondering what is happening internally/in a JavaScript engine when this function is called on e.g. -1.

Solution

  • It runs infinetly because (n == 0) doesnt met

    if you pass a negative number 

    return n * factorial(n - 1)

    invokes factorial function with more negative number recursively and thereby (n == 0) condition doesn't met