jq引入
什么是jQuery:
jQuery是一个简洁高效的且功能丰富的JavaScript工具库,是对原生JavaScript二次封装的工具函数集合
优点:
开源 | 简洁的选择器 | 简化的Ajax操作 | 良好的浏览器兼容 | 强大的链式操作
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>jq引入</title>
<style>
.wrap {
background-color: green;
}
</style>
</head>
<body>
<div class="box">jq引入</div>
<div class="box">jq引入</div>
</body>
<script src="js/jquery-3.3.1.js"></script>
<script>
console.log(jQuery);
console.log($);
$('.box').text("呵呵").css("color", "red").addClass("wrap").on("click", function() {
alert("123");
})
</script>
</html>
jq选择器
$('css3选择器语法');
$('css3选择器语法').eq(index);
$('css3选择器语法').get(index);
$(js对象);
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>jq选择器</title>
<style>
body .box:first-child {
}
</style>
</head>
<body>
<div class="box">123</div>
<div class="box">456</div>
</body>
<script src="js/jquery-3.3.1.js"></script>
<script>
console.log(jQuery);
console.log($);
var $boxs = $('.box');
console.log($boxs)
console.log($boxs.text())
var $box = $('.box:nth-child(1)');
console.log($box);
console.log($box.text());
console.log($box[0].innerText);
var box1 = $boxs[0];
console.log(box1);
var box2 = $boxs.get(1);
console.log(box2)
var $box1 = $(box1);
console.log($box1);
</script>
</html>
页面加载
window