this
1、在普通函数中 this 就指 浏览器顶级对象 window
console.log(this)
2、在事件函数中 this指的是当前触发事件的元素
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<span class="txt">我不喜欢学习!</span>
<script>
window.onload = function () {
var t = document.querySelector('.txt');
t.onclick = function () {
this.innerText = '不,你喜欢!';
}
}
</script>
</body>
</html>
点击后: