js怎么做出点击按钮更换图片
在java script中，应该用什么代码编写可以实现点击按钮，来改变图片，需要用到什么知识
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
div {
width: 400px;
height: 200px;
}
img {
width: 100%;
height: 100%;
}
</style>
</head>
<body>
<span id="text"></span>
<div>
<img id="img" alt="">
</div>
<button id="pret">上一张</button>
<button id="next">下一张</button>
</body>
<script>
//图片地址数组。我用的网络图。你可以自行替换
let imgArr = ["https://gimg2.baidu.com/image_search/src=http%3A%2F%2Ffile03.16sucai.com%2F2016%2F10%2F1100%2F16sucai_p20161004049_098.JPG&refer=http%3A%2F%2Ffile03.16sucai.com&app=2002&size=f9999,10000&q=a80&n=0&g=0n&fmt=jpeg?sec=1627526069&t=254d86f033e2279617c40b2035e57849",
"https://gimg2.baidu.com/image_search/src=http%3A%2F%2Fpic.soutu123.com%2Felement_origin_min_pic%2F16%2F10%2F09%2F0257f936320f509.jpg%21%2Ffw%2F700%2Fquality%2F90%2Funsharp%2Ftrue%2Fcompress%2Ftrue&refer=http%3A%2F%2Fpic.soutu123.com&app=2002&size=f9999,10000&q=a80&n=0&g=0n&fmt=jpeg?sec=1627526146&t=d429d67bd3e56f8f7ff772debe79aff6"
]
let img = document.getElementById("img"); //img标签
let pret = document.getElementById("pret"); //上一个按钮dom
let next = document.getElementById("next"); //下一个按钮dom
let text = document.getElementById("text"); //文字显示
var i = 0;
defaultImg(imgArr, img, i, text);
next.addEventListener("click", () => {
nextFn(imgArr, img)
})
pret.addEventListener("click", () => {
prextFn(imgArr, img)
})
function defaultImg(arr, img, index, text) { //默认的图片 arr-图片数组 。img是图片dom，index-是下标 text-是文字标签dom
img.src = arr[index];
text.innerText = `一共是${arr.length}张，当前是第${index + 1}张`
}
function prextFn(arr) { //上一张
if (i == 0) {
i = arr.length - 1;
img.src = arr[arr.length - 1];//加上这个就是到了第一张，再次点击就回到最后一张，不想要可以注释
text.innerText = `一共是${arr.length}张，当前是第${i + 1}张`
alert("已经是第一张了，在点击就会回到最后一张"); //如果不想这样可以把这三行注释掉
return
}
i--;
img.src = imgArr[i];
text.innerText = `一共是${arr.length}张，当前是第${i}张`
}
function nextFn(arr) { //下一张
if (i == arr.length - 1) {
i = 0;
img.src = arr[0]; //加上这个就是到了最后一张，再次点击就回到第一张，不想要可以注释
text.innerText = `一共是${arr.length}张，当前是第${i + 1}张`
alert("已经是最后一张了，在点击就会回到第一张"); //如果不想这样可以把这三行注释掉
return
}
i++;
img.src = arr[i];
text.innerText = `一共是${arr.length}张，当前是第${i + 1}张`
}
</script>
</html>
可以参考这个 ，主要就是替换 图片的src 路径
```html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>如何用js实现点击图片切换为另一图片，再次点击恢复到原图片</title>
</head>
<body>
<div id="button">
<img id="picts" src="../images/angels.jpg" alt="">
</div>
<script>
function change_pic(){
var button = document.getElementById("button");
var picts = document.getElementById("picts");
button.onclick = function(){
if(picts.getAttribute("src",2) == "../images/angels.jpg"){
picts.setAttribute("src","../images/attrach.jpg");
}else{
picts.setAttribute("src","../images/angels.jpg");
};
}
}
change_pic();
</script>
</body>
</html>
```