javascript prototype½éÉܵÄÎÄÕÂ
JavaScriptÊÇ»ùÓÚ¶ÔÏóµÄ£¬ÈκÎÔªËØ¶¼¿ÉÒÔ¿´³É¶ÔÏó¡£È»¶ø£¬ÀàÐͺͶÔÏóÊDz»Í¬µÄ¡£±¾ÎÄÖУ¬ÎÒÃdzýÁËÌÖÂÛÀàÐͺͶÔÏóµÄÒ»Ð©ÌØµãÖ®Í⣬¸üÖØÒªµÄÊÇÑо¿ÈçºÎд³öºÃµÄ²¢ÇÒÀûÓÚÖØÓõÄÀàÐÍ¡£±Ï¾¹£¬JavaScriptÕâÖÖÁ÷ÐеĽű¾ÓïÑÔÈç¹ûÄܹ»½øÐÐÁ¼ºÃµÄ·â×°£¬²¢ÐγÉÒ»¸öÅÓ´óµÄÀàÐͿ⣬¶ÔÓÚÖØÓÃÊǷdz£ÓÐÒâÒåµÄ¡£
ÍøÉ϶ÔÓÚprototypeµÄÎÄÕºܶ࣬һֱûÃ÷°×ºËÐĵÄ˼Ïë¡£×îºóдÁ˺ܶàÀý×Ó´úÂëºó²ÅÃ÷°×£ºprototypeÖ»ÄÜÓÃÔÚÀàÐÍÉÏ¡£
ÒÔÏÂÊÇһЩ¹ØÓÚÀàÐͺͶÔÏóµÄÀý×Ó£¬´ó¼Ò¿´ÍêÀý×Óºó¿ÉÄܸüÈÝÒ×Àí½âÀàÐͺͶÔÏóÖ®¼äµÄÁªÏµ£º
Àý×Ó´úÂë ˵Ã÷
1 Object.prototype.Property = 1;
Object.prototype.Method = function ()
{
alert(1);
}
var obj = new Object();
alert(obj.Property);
obj.Method();
¿ÉÒÔÔÚÀàÐÍÉÏʹÓÃproptotypeÀ´ÎªÀàÐÍÌí¼ÓÐÐΪ¡£ÕâЩÐÐΪֻÄÜÔÚÀàÐ͵ÄʵÀýÉÏÌåÏÖ¡£
JSÖÐÔÊÐíµÄÀàÐÍÓÐArray, Boolean, Date, Enumerator, Error, Function, Number, Object, RegExp, String
2 var obj = new Object();
obj.prototype.Property = 1; //Error
//Error
obj.prototype.Method = function()
{
alert(1);
}
ÔÚʵÀýÉϲ»ÄÜʹÓÃprototype£¬·ñÔò·¢Éú±àÒë´íÎó
3 Object.Property = 1;
Object.Method = function()
{
alert(1);
}
alert(Object.Property);
Object.Method();
¿ÉÒÔΪÀàÐͶ¨Ò哾²Ì¬”µÄÊôÐԺͷ½·¨£¬Ö±½ÓÔÚÀàÐÍÉϵ÷Óü´¿É
4 Object.Property = 1;
Object.Method = function()
{
alert(1);
}
var obj = new Object();
alert(obj.Property); //Error
obj.Method(); //Error
ʵÀý²»Äܵ÷ÓÃÀàÐ͵ľ²Ì¬ÊôÐÔ»ò·½·¨£¬·ñÔò·¢Éú¶ÔÏó䶨ÒåµÄ´íÎó¡£
5 function Aclass()
{
this.Property = 1;
this.Method = function()
{
alert(1);
}
}
var obj = new Aclass();
alert(obj.Property);
obj.Method();
Õâ¸öÀý×ÓÑÝʾÁËͨ³£µÄÔÚJavaScriptÖж¨ÒåÒ»¸öÀàÐ͵ķ½·¨
6 function Aclass()
{
this.Property = 1;
this.Method = function()
{
alert(1);
}
}
Aclass.prototype.Property2 = 2;
Aclass.prototype.Method2 = function
{
alert(2);
}
var obj = new Aclass();
alert(obj.Property2);
obj.Method2();
¿ÉÒÔÔÚÍ
Ïà¹ØÎĵµ£º
Regular Expression Optimization ÕýÔò±í´ïʽÓÅ»¯
Incautiously crafted regexes can be a major performance bottleneck (the upcoming section, "Runaway Backtracking" on page 91, contains several examples showing how severe this can be), but there is a lot you can do to improve re ......
A Note on Benchmarking ²âÊÔ»ù׼˵Ã÷
Because a regex's performance can be wildly different depending on the text it's applied to, there's no straightforward way to benchmark regexes against each other. For the best result, you need to benchmark your regexes on test strings o ......
µÚÁùÕ Responsive Interfaces ÏìÓ¦½Ó¿Ú
There's nothing more frustrating than clicking something on a web page and having nothing happen. This problem goes back to the origin of transactional web applications and resulted in the now-ubiquitous "please click only once" m ......
ÐÂÖÐ……
1¡¢Êý¾ÝÀàÐÍÑéÖ¤ÎÊÌâ
Asp.NetËäÈ»ÓÐÑéÖ¤¿Ø¼þ£¬µ«ÊÇÓÐЩ¸´ÔÓµÄÑéÖ¤»¹Êǵô«µ½·þÎñÆ÷ÉϽøÐУ¬ÓÃjsËٶȺÍÐÔÄܶ¼±È½ÏºÃ
<script>
//¼ì²éÊÇ·ñΪÈÎÒâÊý£¨ÊµÊý£©
function isNumeric(strNumber) {
var newPar=/^(-|\+)?\d+(\.\d+)?$/
alert(newPar.test(strNumber)); }
//¼ ......
ÐÂÖÐ……
1¡¢Êý¾ÝÀàÐÍÑéÖ¤ÎÊÌâ
Asp.NetËäÈ»ÓÐÑéÖ¤¿Ø¼þ£¬µ«ÊÇÓÐЩ¸´ÔÓµÄÑéÖ¤»¹Êǵô«µ½·þÎñÆ÷ÉϽøÐУ¬ÓÃjsËٶȺÍÐÔÄܶ¼±È½ÏºÃ
<script>
//¼ì²éÊÇ·ñΪÈÎÒâÊý£¨ÊµÊý£©
function isNumeric(strNumber) {
var newPar=/^(-|\+)?\d+(\.\d+)?$/
alert(newPar.test(strNumber)); }
//¼ ......