JavaScript constructorÊôÐÔ
Definition and Usage
¶¨ÒåÓëÓ÷¨The constructor property is a reference to the function that created an object.
constructorÊôÐÔÊÇËù½¨Á¢¶ÔÏóµÄº¯Êý²Î¿¼Syntax
Óï·¨object.constructor
Example 1
¾ÙÀý
In this example we will show how to use the constructor property:
ÔÚÕâ¸ö¾ÙÀýÖÐÎÒÃǽ«Õ¹Ê¾ÈçºÎʹÓÃconstructorÊôÐÔ£º
<script type="text/javascript">
var test=new Array()
if (test.constructor==Array)
{document.write("This is an Array")}
if (test.constructor==Boolean)
{document.write("This is a Boolean")}
if (test.constructor==Date)
{document.write("This is a Date")}
if (test.constructor==String)
{document.write("This is a String")}
</script>
The output of the code above will be:
Êä³ö½á¹ûΪ£º
This is an Array
Example 2
¾ÙÀý2
In this example we will show how to use the constructor property:
ÔÚÕâ¸ö¾ÙÀýÖÐÎÒÃǽ«Õ¹Ê¾ÈçºÎʹÓÃconstructorÊôÐÔ£º
<script type="text/javascript">
function employee(name,jobtitle,born)
{
this.name=name
this.jobtitle=jobtitle
this.born=born
}
var fred=new employee("Fred Flintstone","Caveman",1970)
document.write(fred.constructor)
</script>
The output of the code above will be:
Êä³ö½á¹ûΪ£º
function employee(name, jobtitle, born)
{this.name = name; this.jobtitle = jobtitle; this.born = born;}
Try-It-Yourself Demos
³¢ÊÔÓëÑÝʾ
constructor - example 1
In this example we will show how to use the constructor property.
ÔÚÕâ¸ö¾ÙÀýÖÐÎÒÃǽ«Õ¹Ê¾ÈçºÎʹÓÃconstructorÊôÐÔ
constructor - example 2
In this example we will show how to use the constructor property.
ÔÚÕâ¸ö¾ÙÀýÖÐÎÒÃǽ«Õ¹Ê¾ÈçºÎʹÓÃconstructorÊôÐÔ
http://www.w3pop.com/learn/view/doc/jsref_constructor_array/
Ïà¹ØÎĵµ£º
1. Ó¦Óà Array.prototype.joinʵÏÖ×Ö·ûºÏ²¢
·½·¨1.
String.prototype.times = function(n) {
return Array.prototype.join.call({length:n+1}, this);
};
"js".times(5) // => "jsjsjsjsjs"
·½·¨2.
var ArrayTest=new Array("HE","LL","O");
var hello = Array.prot ......
ʾÀý£º
- - - - - - - - - - - -
<body>
<input type="button" value="create" onclick="createTr();">
<table border='1' id="t" >
</table>
<input type="button" value="Ìá½»" onclick="okss();" />
</body>
<script type="text/javascript">
&nbs ......
1. oncontextmenu="window.event.returnValue=false" ½«³¹µ×ÆÁ±ÎÊó±êÓÒ¼ü
<table border oncontextmenu=return(false)><td>no</table> ¿ÉÓÃÓÚTable
2. <body onselectstart="return false"> È¡Ïûѡȡ¡¢·ÀÖ¹¸´ÖÆ
3. onpaste="return false" ²»×¼Õ³Ìù
4. oncopy="return false;" oncut="return f ......
reg = /^((((((0[48])|([13579][26])|([2468][048]))00)|([0-9][0-9]((0[48])|([13579][26])|([2468][048]))))-02-29)|(((000[1-9])|(00[1-9][0-9])|(0[1-9][0-9][0-9])|([1-9][0-9][0-9][0-9]))-((((0[13578])|(1[02]))-31)|(((0[1,3-9])|(1[0-2]))-(29|30))|(((0[1-9])|(1[0-2]))-((0[1-9])|(1[0-9])|(2[0-8]))))))$/i; ......
ÀàµÄ¶¨ÒåÓÐ3ÖÖ»ù±¾·½·¨:
1¡¢´´½¨²¢ÄÜ·µ»ØÌض¨ÀàÐ͵ĶÔÏóµÄº¯Êý(¹¤³§º¯Êý)È磺
function wu()
{
var w=new object;
o.a=1;
return o;
}ÓÃÕâÖÖ·½Ê½´´½¨¶ÔÏó£ºvar u=wu();
2¡¢´´½¨¹¹Ô캯Êý£¬ÓÃnewʵÀý»¯ÀýÈ磺
function wu()
{this.a=1;}
ÓÃÕâÖÖ·½Ê½´´½¨¶ÔÏó: var u=new wu();
3¡¢ÔÐÍ·½Ê½,À ......