JQuery determines whether the checkbox of checkbox is selected and whether the implementation code is fully or unselected

2020-03-30 02:04:17
OfStack

JQuery determines if a checkbox is selected:
If ($(" # id "). The attr (" checked ") = = true)

JQuery implements checkbox selection, full selection/unselection code:


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>jQuery How to determine checkbox (check box) whether or not selected and all or none selected </title>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
<!--
$("document").ready(function(){
 $("#all").click(function(){   
  if(this.checked){   
   $("input[name='checkbox']").each(function(){this.checked=true;});
   $("#btn1").attr("value"," The selected ");   
  }else{   
   $("input[name='checkbox']").each(function(){this.checked=false;});   
   $("#btn1").attr("value"," Future generations "); 
  }   
 });

 $("#btn1").click(function(){
  $("[name='checkbox']").attr("checked",'true');// Future generations 
 });

 $("#btn2").click(function(){
  $("[name='checkbox']").removeAttr("checked");//To cancel all
 });

 $("#btn3").click(function(){
  $("[name='checkbox']:even").attr("checked",'true');//Select all odd Numbers
 });

 $("#btn4").click(function(){
  $("[name='checkbox']").each(function(){
   if($(this).attr("checked"))
   {
    $(this).removeAttr("checked");
   }else{
    $(this).attr("checked",'true');
   }
  });
 });

 $("#btn5").click(function(){
  var str="";
  //$("input:checkbox[name='checkbox']:checked").each(function(){// can 
  $("[name='checkbox'][checked]").each(function(){
   str+=$(this).val()+"rn";
  });
  alert(str);
 });
});
//-->
</script>
</head>
<body>
    <form name="form1" method="post" action="">
     <input type="checkbox" id="all" name="all">
        <input type="button" id="btn1" value=" Future generations ">
        <input type="button" id="btn2" value="To cancel all">
        <input type="button" id="btn3" value="Select all odd Numbers">
        <input type="button" id="btn4" value=" The selected ">
        <input type="button" id="btn5" value=" Gets all the selected values ">
        <br />
        <input type="checkbox" name="checkbox" value="checkbox1">checkbox1
        <input type="checkbox" name="checkbox" value="checkbox2">checkbox2
        <input type="checkbox" name="checkbox" value="checkbox3">checkbox3
        <input type="checkbox" name="checkbox" value="checkbox4">checkbox4
        <input type="checkbox" name="checkbox" value="checkbox5">checkbox5
        <input type="checkbox" name="checkbox" value="checkbox6">checkbox6
        <input type="checkbox" name="checkbox" value="checkbox7">checkbox7
        <input type="checkbox" name="checkbox" value="checkbox8">checkbox8
    </form>
</body>
</html>