全选和反选的js作业
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style>
</style>
<script>
function checkall(){
var all,checks;
all=document.getElementById('all');
checks=document.getElementsByName('item[]');
for(var i=0;i<checks.length;i++){
if(all.checked){
checks[i].checked=true;
}else{
checks[i].checked=false;
}
}
}
</script>
</head>
<body>
<input type="checkbox" id="all" onclick="checkall();"> <label for="all">全选</label><br>
<input type="checkbox" name="item[]">多选框1<br>
<input type="checkbox" name="item[]">多选框2<br>
<input type="checkbox" name="item[]">多选框3<br>
<input type="checkbox" name="item[]">多选框4<br>
<input type="checkbox" name="item[]">多选框5<br>
<input type="checkbox" name="item[]">多选框6<br>
<input type="checkbox" name="item[]">多选框7<br>
</body>
</html>