<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>test</title>
</head>
<style>
</style>
<body>
<ul>
<li>
<img src="1.jpg" alt="">
</li>
<li>
<img src="1.jpg" alt="">
</li>
</ul>
<button>惦记我</button>
<script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js"></script>
<script>
var totalnum = 7;
function addNum(number) {
var latestSub= jQuery('ul li').length,
num = totalnum - latestSub,
laterSub;
if (num < number) {
laterSub = totalnum;
} else {
laterSub = latestSub + number;
}
for (var i = latestSub; i < laterSub; i++) {
var li = document.createElement('li'),
img = document.createElement('img');
img.src = "1.jpg";
li.appendChild(img);
jQuery('ul').append(li);
}
}
jQuery('button').off('click').on('click', function () {
addNum(3);
})
</script>
</body>
</html>
