为什么clearInterval在我的脚本中不起作用？

Question

I have got a problem with my clearInterval method. I learn about JS in depth at FrontendMasters and there is an exercise where you need to use setInterval and log a string at every second and then run clearInterval after 5 seconds. I have access to the right solution but I would like to know why my solution is not working to get better understanding. The console.log('clear called', func); runs after 5 seconds and log the clear called string and the function body. I have tried to use setTimeout to wrap wrapper.stop() but it did not work that way either. I have used closures to try to solve the exercise. Here is my script.

function sayHowdy() {
 console.log('Howdy');
}


function everyXsecsForYsecs(func, interval, totalTime) {
 function clear() {
   console.log('clear called', func);
   clearInterval(func);
 }
 return {
   start() {
     setInterval(func, interval);
   },
   stop() {
     setTimeout(clear, totalTime);
   }
 }
}


const wrapper = everyXsecsForYsecs(sayHowdy, 1000, 5000);
wrapper.start();
wrapper.stop();

Thanks

Answer 1

clearInterval does not take a function but a timer id which gets returned when using setInterval (so that you can set multiple timers onto the same function, and cancel them individually). To use that, declare a local variable inside everyXsecsForYsecs

  var timer;

Then assign the timer to it:

 timer = setInterval(func, interval);

Then you can clearInterval(timer) .