Js word form operator
- 2020-03-30 02:50:48
- OfStack
1. Void operand and ignore its return value, such as void (1+2),void (0)
<html>
<head>
<meta http-equiv="content-type" charset="utf-8"/>
<script type="text/javascript">
alert(typeof(void(0))); //Void (0) evaluates to 0, typeof is: undefined because the return value is ignored
</script>
</head>
<body>
1. with onclick Flexible handling of events; 2.void(expression)<br>
<a href="javascript:void(0);" onclick="location.href='http://www.baidu.com';"> baidu </a>
<a href="javascript:void(location.href='http://www.google.com')"> Google </a>
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Typeof returns the typeof a variable or value, such as typeof(void 1+2),typeof(void(1+2)).
Because of the operator priority, the operation process of void 1+2 is:
< img SRC = "border = 0 / / files.jb51.net/file_images/article/201405/20140506104849.jpg? 201446104952 ">
3. New is used to create the object real column of the specified class
4. Delete deletes the real column property. There are several points to note about delete:
1. Delete only real column properties, not objects
<html>
<head>
<meta http-equiv="content-type" charset="utf-8"/>
<script type="text/javascript">
var parent={};
var son={age:10};
parent.son=son;
alert(parent.son.age);//10
delete parent.son;
alert(parent.son);//undefined
alert(son.age);//10
</script>
</head>
<body>
</body>
</html>