How to implement timers in JavaScript?

In JavaScript, you can use timer functions to achieve timed tasks. Commonly used timer functions include setTimeout() and setInterval().

1. delay the execution of code

setTimeout(function, delay);

In this case, the function refers to the function to be executed, while the delay is the time to wait, measured in milliseconds.

For example, the following code will output “Hello, World!” after 1 second:

setTimeout(function() {
  console.log("Hello, World!");
}, 1000);

1. Set a recurring interval定期地。

setInterval(function, delay);

In this case, function refers to the function to be executed, while delay refers to the time interval in milliseconds.

For example, the following code will output “Hello, World!” every 1 second.

setInterval(function() {
  console.log("Hello, World!");
}, 1000);

It is important to note that the timer returns a unique identifier, which can be used to cancel the timer using the clearTimeout() and clearInterval() functions.

For example, the following code will cancel the timer after 3 seconds:

var timerId = setTimeout(function() {
  console.log("Hello, World!");
}, 3000);

// 取消定时器
clearTimeout(timerId);

The above is the method of implementing a timer in JavaScript.