Requirements :
1) elected in Select this check box, the following check boxes will also be selected, when unchecked, the following check boxes are selected.
2) When the following check boxes are selected, select all the above are also selected.
Directly on the bar code:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>demo</title>
</head>
<script>
function allCheck(){
var status=document.getElementById("allcheck").checked;
var btn=document.getElementsByName("check");
for(var i=0;i<btn.length;i++){
btn[i].checked=status;
}
}
function check(){
var flag=true;
var all=document.getElementById("allcheck");
var btn=document.getElementsByName("check");
for(var i=0;i<btn.length;i++){
if(btn[i].checked!=flag){
flag=false;
break;
}
}
all.checked=flag;
}
</script>
<body>
<input type="checkbox" id="allcheck" onclick="allCheck()"/>全选/全不选<br />
<input type="checkbox" name="check" onclick="check()"/>西瓜
<input type="checkbox" name="check" onclick="check()"/>苹果
<input type="checkbox" name="check" onclick="check()"/>香蕉
</body>
</html>
