javascript中的递归和函数调用

Question

 function test(param, n) { console.log(param, "start --- ", n); if (n > 1) { console.log(param, "before first recursion --- ", n); test("test-1", n - 1); console.log(param, "after first recursion --- ", n); test("test-2", n - 1); console.log(param, "after second recursion --- ", n); } console.log(param, "end --- ", n); } test("initialize", 3);

In output console

test-1 after first recursion --- I am getting value 2 , can someone please explain the flow of code is going as, I was expecting 3 as the output, because in my understanding if the test("test-1", n-1) is completed then the next call ie test("test-2", n-1) will be getting 3 value as fresh input, also is the js working synchronous here ?

Answer 1

You could use some indentations to the output and look which level is actually running.

 function test(param, n, level = 0) { console.log(''.padStart(level * 2), level, param, "start --- ", n); if (n > 1) { test("test-1", n - 1, level + 1); test("test-2", n - 1, level + 1); } console.log(''.padStart(level * 2), level, param, "end --- ", n); } test("initialize", 3);