使用数组更改javascript背景图像

Question

我不是经验丰富的 javascript 程序员，所以我尝试使用 javascript。我正在尝试通过单击按钮制作幻灯片。函数我正在尝试使用数组创建一个函数，该函数包含所有图像的名称并根据数组的索引更改背景图像。我只完成了这部分功能，但我看不出哪里出了问题。

function change(lol){
	var img = ["veni1.jpg", "veni2.jpg", "veni3"];
    var middle = document.getElementById("vvvmiddle");
    var index = img.indexOf(middle.style.backgroundImage);
  
	if(change === "right"){
		var current = index + 1;
		middle.style.backgroundImage = img[current];
	}
}

middle {
    width:1262px;
    height:550px;
    background-color: white;
    margin-left: -7px;
}
#vvvmiddle {
    width:700;
    height:400;
    background-image:url('veni1.jpg');
    margin: 20px 0px 0px 310px;
    float:left;
}
#sipka {
    width:40;
    height:40;
    border-radius: 100px;
    background-color: #DCDCDC;
    float:right;
    margin: 450px 410px 0px 0px;
}
#sipkatext {
    font-family: Impact;
    color: white;
    font-size: 30px;
    padding-left: 10px;
    padding-top: 1px;
}
#sipkaurl {
    text-decoration: none;
}
#sipka:hover {
    background-color: #3399FF;
}
#sipka2:hover {
    background-color: #3399FF;
}
#sipka2 {
    width:40;
    height:40;
    border-radius: 100px;
    background-color: #DCDCDC;
    float:right;
    margin: 450px -100px 0px 0px;
}
#sipkatext2 {
    font-family: Impact;
    color: white;
    font-size: 30px;
    padding-left: 13px;
    padding-top: 1px;
}

<div id="middle">
    <div id="vvvmiddle">
        <div id="sipka" onclick="change('left')">
            <div id="sipkatext">
                <</div>
            </div>
            <div id="sipka2" onclick="change('right')">
                <div id="sipkatext2">></div>
            </div>
        </div>
    </div>

Answer 1

一个可能的解决方案可能是这个:

var img = ["img1.png", "img2.png", "img3.png"];
var len = img.length;
var url = 'Some url...';
var current=0;

var middle = document.getElementById("vvvmiddle");
middle.style.backgroundImage = "url(" + url + img[current] + ")";

function change(dir){
    if(dir == "right" && current < len-1){
        current++;
        middle.style.backgroundImage = "url(" + url + img[current] + ")";
    } else if(dir == "left" && current > 0){
        current--;
        middle.style.backgroundImage = "url(" + url + img[current] + ")";
    }
}

查看实际效果，在此处查看 jsfiddle .