nodejs完成后如何再次调用函数

Question

Let's say I have a function,

function hello(){
  console.log('hello world');
}

Now I want to call this function again, as soon as it finishes. So I do something like this:

function hello(){
  console.log('hello world');
  hello();
}

However, doing this does not work as expected, because due to the asynchronous nature of nodejs, hello is called again before console.log('hello world'); finishes executing.

Is there a way to run the function hello repeatedly, but wait until it finishes before it runs for a second time?

Answer 1

Your problem isn't the asynchronous nature of JavaScript. Rather, it's that you have an infinite recursion and that quickly causes a RangeError: Maximum call stack size exceeded to protect you from consuming all of a machines memory with a giant stack of function calls.

You are not required to have a stopping condition. You can actually use the asynchronous nature of JavaScript to fix it:

 function hello(){ console.log('hello world'); setTimeout(hello, 0); } hello();