js全选反选
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style>
#box{
width:150px;
height:150px;
background-color:red;
}
</style>
</head>
<body>
<input type="checkbox" id="all"><label for="all">全选</label>
<hr>
<input type="checkbox" name="check[]" id="nth1"><label for="nth1">选项</label>
<input type="checkbox" name="check[]" id="nth2"><label for="nth2">选项</label>
<input type="checkbox" name="check[]" id="nth3"><label for="nth3">选项</label>
<input type="checkbox" name="check[]" id="nth4"><label for="nth4">选项</label>
<input type="checkbox" name="check[]" id="nth5"><label for="nth5">选项</label>
<input type="checkbox" name="check[]" id="nth6"><label for="nth6">选项</label>
<script>
document.getElementById('all').onclick = function(){
var a = document.getElementsByName('check[]');
for(i=0; i<a.length; i++){
if(document.getElementById('all').checked){
a[i].checked = true;
}else{
a[i].checked = false;
}
}
}
</script>
</body>
</html>利用循环和if判断来实现功能