setInterval 函数中的变量增量器 [英] variable incrementer in setInterval function

问题描述

我的函数有很多问题，我对变量作用域感到困惑.我尝试使用回调函数，但无法获取.

I have lot of problems with a function and I get confused with the variable scope. I tried with a callback function, but I cannot get it.

我有一个使用 css 为背景设置动画的功能.当我在 setInterval 运行时第二次单击时，我需要该函数不会将 incrementer 变量重新启动为 0.看到当你在html的time1或time2点击两次a时，counter的顺序不持有顺序.

I have a function to animate a background with css. I need that function doesn't restart the incrementer variable to 0 when I click for a second time while a setInterval is running. See that when you click a twice in time1 or time2 of html, the order of counter doesn't hold the order.

function movie(elm,jumpPx,spriteHeight,duration){
var inc=0;
var time=setInterval(function(){

    if(inc<spriteHeight){
        inc+=jumpPx;
        //elm.style.backgroundPosition='0px -'+inc+'px';
        elm.innerHTML=inc;
    }else{
        clearInterval(time);
        elm.style.backgroundPosition='0px -0px';          
    }
},duration);  

}

<p onclick="movie(this,1,1000,1000)">time1</p>
<p onclick="movie(this,1,1000,1000)">time2</p>

推荐答案

你的变量声明在函数内:

Your variable declaration is within the function:

function movie(elm,jumpPx,spriteHeight,duration){
    var inc=0;
    ... other code ...
}

因此，每次调用该函数时，都会将 'inc' 重置为 0.

Therefore, each time the function is called, it resets 'inc' to 0.

var inc = 0;
function movie(elm,jumpPx,spriteHeight,duration){
    ... other code ...
}

如果你把它移到函数外，它不会一直重置

If you move it outside the function, it won't keep resetting

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