Simulate sleep in Javascript

There are several methods, but they are not perfect.

 

First, keep repeating until the specified time is reached

Function sleep (numbermillis) {var now = new date (); var exittime = now. gettime () + numbermillis; while (true) {now = new date (); If (now. gettime ()> exittime) return ;}}

ActuallyCodeThe script is not sleep down, but the CPU is quickly attached to high load. Most modern browsers will be suspended for some time.

 

Second, use xhr to synchronize requests to the backgroundProgramFor example, if 2000 is passed, the backend will sleep for 2 seconds and then return. This method also has some disadvantages. When n clients request the backend, the connection HTTP overhead will remain high.

 

In addition, the alert and confirm of the window object can interrupt subsequent code execution.