Typescript 中 setTimeout() 的返回类型是什么

Typescript 中 setTimeout() 的返回类型

What’s the Return Type for setTimeout() in Typescript

使用ReturnType实用程序类型获取setTimeout
方法的返回类型，例如const timeout: ReturnType<typeof setTimeout> = setTimeout()。ReturnType实用程序类型构造一个由函数的返回类型组成的类型。

const timeout: ReturnType<typeof setTimeout> = setTimeout(() => {
  console.log('success');
}, 1500);

console.log(timeout);

ReturnType
实用程序类型允许我们构造一个由传入函数的返回类型组成的类型。

function sum(a: number, b: number) {
  return a + b;
}

// 👇️ type T = number
type T = ReturnType<typeof sum>;

需要这种方法，因为
setTimeout方法的返回类型NodeJS.Timeout在 Node 和number浏览器中。

It should be noted that even though the return type of the setTimeout method
is different between Node.js and the browser, the return value is used in the
same way – it is passed to the clearTimeout() method to cancel the timeout if
necessary.

const timeout: ReturnType<typeof setTimeout> = setTimeout(() => {
  console.log('success');
}, 1500);

clearTimeout(timeout);

The clearTimeout method takes a number or a NodeJS.Timeout object as a
parameter (depending on the environment), so you can directly pass the timeout
value to the method.