Ò׽ؽØÍ¼Èí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

JavaScript apply¡¢call·½·¨ºÍlengthÊôÐÔ

JavaScriptΪº¯Êý¶ÔÏó¶¨ÒåÁËÁ½¸ö·½·¨£ºapplyºÍcall£¬ËüÃǵÄ×÷Óö¼Êǽ«º¯Êý°ó¶¨µ½ÁíÍâÒ»¸ö¶ÔÏóÉÏÈ¥ÔËÐУ¬Á½Õß½öÔÚ¶¨Òå²ÎÊýµÄ·½Ê½ÓÐËùÇø±ð£º
Function.prototype.apply(thisArg,argArray);
Function.prototype.call(thisArg[,arg1[,arg2…]]);
´Óº¯ÊýÔ­ÐÍ¿ÉÒÔ¿´µ½£¬µÚÒ»¸ö²ÎÊý¶¼±»È¡ÃûΪthisArg£¬¼´ËùÓк¯ÊýÄÚ²¿µÄthisÖ¸Õë¶¼»á±»¸³ÖµÎªthisArg£¬Õâ¾ÍʵÏÖÁ˽«º¯Êý×÷ΪÁíÍâÒ»¸ö¶ÔÏóµÄ·½·¨ÔËÐеÄÄ¿µÄ¡£Á½¸ö·½·¨³ýÁËthisArg²ÎÊý£¬¶¼ÊÇΪFunction¶ÔÏ󴫵ݵIJÎÊý¡£ÏÂÃæµÄ´úÂë˵Ã÷ÁËapplyºÍcall·½·¨µÄ¹¤×÷·½Ê½£º
function func1(){
      this.p="func1-";
      this.A=function(arg){
            alert(this.p+arg);
      }
}
function func2(){
      this.p="func2-";
      this.B=function(arg){
             alert(this.p+arg);
      }
}
var obj1=new func1();
var obj2=new func2();
obj1.A("byA");     //ÏÔʾfunc1-byA
obj2.B("byB");     //ÏÔʾfunc2-byB
obj1.A.apply(obj2,["byA"]); //ÏÔʾfunc2-byA£¬ÆäÖÐ[“byA”]ÊǽöÓÐÒ»¸öÔªËØµÄÊý×飬ÏÂͬ
obj2.B.apply(obj1,["byB"]); //ÏÔʾfunc1-byB
obj1.A.call(obj2,"byA");   //ÏÔʾfunc2-byA
obj2.B.call(obj1,"byB");   //ÏÔʾfunc1-byB
¿ÉÒÔ¿´³ö£¬obj1µÄ·½·¨A±»°ó¶¨µ½obj2ÔËÐкó£¬Õû¸öº¯ÊýAµÄÔËÐл·¾³¾Í×ªÒÆµ½ÁËobj2£¬¼´thisÖ¸ÕëÖ¸ÏòÁËobj2¡£Í¬Ñùobj2µÄº¯ÊýBÒ²¿ÉÒ԰󶨵½obj1¶ÔÏóÈ¥ÔËÐС£´úÂëµÄ×îºó4ÐÐÏÔʾÁËapplyºÍcallº¯Êý²ÎÊýÐÎʽµÄÇø±ð¡£
ÓëargumentsµÄlengthÊôÐÔ²»Í¬£¬º¯Êý¶ÔÏó»¹ÓÐÒ»¸öÊôÐÔlength£¬Ëü±íʾº¯Êý¶¨ÒåʱËùÖ¸¶¨²ÎÊýµÄ¸öÊý£¬¶ø·Çµ÷ÓÃʱʵ¼Ê´«µÝµÄ²ÎÊý¸öÊý¡£ÀýÈçÏÂÃæµÄ´úÂ뽫ÏÔʾ2£º
function sum(a,b){
      return a+b;
}
alert(sum.length);


Ïà¹ØÎĵµ£º

CºÍPython³ÌÐòÔ±µÄJavaScriptѧϰָÄÏ£¨Ò룩


write by ¾ÅÌìÑãôá(JTianLing) -- blog.csdn.net/vagrxie
ÌÖÂÛÐÂÎÅ×é¼°Îļþ
 Ô­ÎÄÀ´×Ô£º¡¶JavaScript for C & Python programmers
¡·£¬¾­¹ý×÷ÕßCanisÔÊÐíºó·­Ò룬¼´Ê¹×ªÔØÇ븽´ø´ËÁ´½Ó¡£

ǰÑÔ£ººÜÉٸɷ­ÒëµÄÊÂÇ飬ÀÛ£¬ÐÁ¿à£¬²»ÄÜ·¢»Ó£¬µäÐ͵ķÑÁ¦²»Ìֺã¬×î½üÎÞÁÄ£¬ÏëÔÚÍøÒ³ÉÏÏÔʾ¶¯»­£¨ÒòΪCSDNÌ ......

javascript£º»ñÈ¡ÆÁÄ»¸ß¶ÈºÍ¿í¶ÈµÈÐÅÏ¢

ÍøÒ³¿É¼ûÇøÓò¿í£º document.body.clientWidth
ÍøÒ³¿É¼ûÇøÓò¸ß£º document.body.clientHeight
ÍøÒ³¿É¼ûÇøÓò¿í£º document.body.offsetWidth (°üÀ¨±ßÏߵĿí)
ÍøÒ³¿É¼ûÇøÓò¸ß£º document.body.offsetHeight (°üÀ¨±ßÏߵĸß)
ÍøÒ³ÕýÎÄÈ«ÎÄ¿í£º document.body.scrollWidth
ÍøÒ³ÕýÎÄÈ«Îĸߣº document.body.scrollHeight ......

JavaScriptʵÏÖÒ³ÃæÌø×ªµÄ¼¸ÖÖ·½Ê½

     
1. °´Å¥Ê½£º
¡¡¡¡<INPUT name="pclog" type="button" value="GO" onClick="location.href='http://xxxx.cn/'">
¡¡¡¡
2. Á´½Óʽ£º
¡¡¡¡<a href="javascript:history.go(-1)">·µ»ØÉÏÒ»²½</a>
¡¡¡¡<a href="<%=Request.ServerV ......

×Ô¶¯µãÍøÒ³ÖеÄJavaScriptÁ´½Ó


‘µãÕý³£Á´½Ó·½·¨ºÜ¶à£¬ÕâÀï½éÉܵÄÊÇ×Ô¶¯µãJavaScriptÁ´½Ó
Function RunJS(scripts)
‘VB ×Ô¶¯µãÍøÒ³ÖеÄJavascriptÁ´½Ó
Dim Document
                On Error GoTo ErrHandle
        ......

Àí½â JavaScript ±Õ°ü{×ªÔØ}

¡¾×ª¡¿http://www.cnblogs.com/chenxizhang/archive/2010/01/02/1638010.html
±¾ÎÄ×ªÔØ×Ô£ºhttp://www.cn-cuckoo.com/2007/08/01/understand-javascript-closures-72.html
Òª³ÉΪ¸ß¼¶ JavaScript ³ÌÐòÔ±£¬¾Í±ØÐëÀí½â±Õ°ü¡£
±¾ÎĽáºÏ ECMA 262 ¹æ·¶Ïê½âÁ˱հüµÄÄÚ²¿¹¤×÷»úÖÆ£¬Èà JavaScript ±à³ÌÈËÔ±¶Ô±Õ°üµÄÀí½â´Ó&ldquo ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ