尝试使用 javascript 使用递归打印数字的阶乘，但没有给出预期的输出

Question

Trying to print the factorial of a number with recursion using javascript but its not giving the expected output.

function factorialRecursion(n){
return n * factorialRecursion(n - 1);
}
factorialRecursion(6);

Uncaught RangeError: Maximum call stack size exceeded at factorialRecursion (eval at factorial ( enter code here index.html:3), :1:28) at factorialRecursion (eval at factorial (index.html:3), :3:13) at factorialRecursion (eval at factorial (index.html:3), :3:13) at factorialRecursion (eval at factorial (index.html:3), :3:13) at factorialRecursion (eval at factorial (index.html:3), :3:13) at factorialRecursion (eval at factorial (index.html:3), :3:13) at factorialRecursion (eval at factorial (index.html:3), :3:13) at factorialRecursion (eval at factorial (index.html:3), :3:13) at factorialRecursion (eval at factorial (index.html:3), :3:13) at factorialRecursion (eval at factorial (index.html:3), :3:13)

Answer 1

The stack overflows because there is no base case .

• to calculate factorial(6) , you need to know the answer to factorial(5)
• to calculate factorial(5) , you need to know the answer to factorial(4)
• ...
• to calculate factorial(1) , you need to know the answer to factorial(0)
• to calculate factorial(0) , you need to know the answer to factorial(-1)
• to calculate factorial(-1) , you need to know the answer to factorial(-2)
• ...

Above we see the original program just continues n - 1 infinitely, until the stack overflows.

A fix to your program might look like -

 function factorial(n) { if (n <= 0) // <-- base case return 1 else // <-- inductive case (n > 0) return n * factorial(n - 1) } console.log(factorial(6)) // 720