javascript - 递归函数和 setTimeout

声明:本页面是StackOverFlow热门问题的中英对照翻译,遵循CC BY-SA 4.0协议,如果您需要使用它,必须同样遵循CC BY-SA许可,注明原文地址和作者信息,同时你必须将它归于原作者(不是我):StackOverFlow 原文地址: http://stackoverflow.com/questions/7246441/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me): StackOverFlow

提示:将鼠标放在中文语句上可以显示对应的英文。显示中英文
时间:2020-10-25 23:26:42  来源:igfitidea点击:

javascript - recursive function & setTimeout

javascriptsettimeout

提问by mustapha george

I am trying to write a javascript function that when called performs function DoSomething() once, but can be triggered to perform the function repeatedly until triggered to stop.

我正在尝试编写一个 javascript 函数,该函数在调用时执行一次函数 DoSomething(),但可以被触发以重复执行该函数,直到被触发停止。

I am using setTimeout() function. I am not sure if this is best method from performance and memory point of view. Also I would like to avoid global variable if possible

我正在使用 setTimeout() 函数。从性能和内存的角度来看,我不确定这是否是最佳方法。如果可能的话,我也想避免全局变量

<!DOCTYPE html>
<html>
    <script src="jquery.js"></script>

    <script>
    var globalCheckInventory = false;

    $(document).ready(function(){
        // start checking inventory
        globalCheckInventory = true;                 
        myTimerFunction();  
    }); 

    // check inventory at regular intervals, until condition is met in DoSomething
    function myTimerFunction(){
        DoSomething();
        if (globalCheckInventory == true)
        {
            setTimeout(myTimerFunction, 5000);      
        }           
    }

    // when condition is met stop checking inventory
    function DoSomething() {     
        alert("got here 1 ");
        var condition = 1;
        var state = 2 ;
        if (condition == state)
        {
            globalCheckInventory = false;
        }        
    }
    </script>

采纳答案by g.d.d.c

This is probably the easier way to do what you're describing:

这可能是执行您所描述的操作的更简单方法:

$(function () {
  var myChecker = setInterval(function () {
    if (breakCondition) {
      clearInterval(myChecker);
    } else {
      doSomething();
    }
  }, 500);
});

回答by Alex Turpin

Another way to do it would be the store the timer ID and use setIntervaland clearInterval

另一种方法是存储计时器 ID 并使用setIntervalclearInterval

var timer = setInterval(DoSomething);

function DoSomething() {
    if (condition)
        clearInterval(timer);
}

回答by sholsinger

I see nothing wrong with your implementation other than the pollution of the global namespace. You can use a closure (self-executing function) to limit the scope of your variables like this:

除了全局命名空间的污染之外,我认为您的实现没有任何问题。您可以使用闭包(自执行函数)来限制变量的范围,如下所示:

(function(){

  var checkInventory = false, inventoryTimer;

  function myTimerFunction() { /* ... */ }

  function doSomething() { /* ... */ }

  $(document).ready(function(){
    checkInventory = true;
    /* save handle to timer so you can cancel or reset the timer if necessary */
    inventoryTimer = setTimeout(myTimerFunction, 5000);
  });

})();

回答by Geoff Moller

Encapsulate it:

封装它:

function caller(delegate, persist){
    delegate();
    if(persist){
        var timer = setInterval(delegate, 300);
        return {
            kill: function(){
                clearInterval(timer);
            }
        } 
    }   
}
var foo = function(){
    console.log('foo');
}

var _caller = caller(foo, true);
//to stop: _caller.kill()