javascript - JS : loop through array indefinetly

Question

短篇小说我想每 4 秒从一组图像中更改图像。我需要在此处添加什么才能实现此目的。

var list = ["img1", "img2", "img3"];

function ChangeBackground () {
  document.getElementById('background').src = "images/"+list[i];
}

window.setInterval(ChangeBackground(), 4000);

Answer 1

您可以对索引使用闭包。

function changeBackground() {
    var i = 0,
        imgURL = 'http://lorempixel.com/250/200/abstract/';
    return function () {
        document.getElementById('background').src = imgURL + list[i++];
        i %= list.length; // prevent looping over the length
    };
}

var list = [3, 1, 4, 7];

setInterval(changeBackground(), 4000);
//                          ^^         with brackets for returning function 

<img id="background">