javascriptºËÐÄѧϰ±Ê¼Ç
±äÁ¿
1. Èç¹ûûÓÐÓÃvarÓï¾ä¸øÒ»¸ö±äÁ¿¶¨³õʼֵ£¬ËüµÄ³õʼֵ¾ÍÊÇundefined.
2. ³¢ÊÔ¸øδÓÃvarÉùÃ÷µÄ±äÁ¿¸³Öµ£¬JavaScript»áÒþʽÉùÃ÷¸Ã±äÁ¿¡£µ«ÊÇ£¬ÒþʽÉùÃ÷µÄ±äÁ¿×ÜÊDZ»´´½¨ÎªÈ«¾Ö±äÁ¿£¬¼´Ê¹¸Ã±äÁ¿Ö»ÔÚÒ»¸öº¯ÊýÌåÄÚʹÓá£
3. º¯ÊýÖÐÉùÃ÷µÄ±äÁ¿£¬ÎÞÂÛÔÚÄÄÀïÉùÃ÷µÄ£¬ÔÚÕû¸öº¯ÊýÖж¼Óж¨Òå¡£
4. ±äÁ¿±£´æÁË»ù±¾ÀàÐ͵Äʵ¼ÊÖµ£¬µ«ÊǶÔÒýÓÃÀàÐ͵Äֵȴֻ±£´æ¶ÔËûµÄÒýÓá£
±í´ïʽºÍÔËËã·û
1. JavaScriptÖÐËùÓÐÊý×Ö¶¼ÊǸ¡µãÐ͵ġ£
2. = = =ÔËËã·ûÊǵÈͬÔËËã·û£¬Ëü²ÉÓÃÑϸñµÄͳһ¶¨Òå¼ì²âÁ½¸öÔËËãÊýÊÇ·ñÍêÈ«Ïàͬ¡£= = ÔËËã·ûÊÇÏàµÈÔËËã·û£¬Ëü²ÉÈ¡±È½Ï¿íËɵÄͳһÐÔ¶¨Òå¡£
3. NaNÓÀÔ¶²»»áºÍÆäËûÈκÎÖµÏàµÈ£¬°üÀ¨Ëü±¾Éí¡£
4. ±È½Ï¶ÔÏó¡¢Êý×éºÍº¯ÊýʱʹÓõÄÔÔòÊÇÒýÓã¬Ö»ÓÐÁ½¸ö±äÁ¿ÒýÓõÄÊÇͬһ¸ö¶ÔÏóʱ£¬ËûÃDzÅÊÇÏàµÈµÄ¡£
5. Èç¹ûÒ»¸öÖµÊÇnull£¬ÁíÒ»¸öÖµÊÇundefined,ËüÃÇÏàµÈ¡£
6. ×Ö·û´®µÄ±È½ÏÊÇÑϸñ°´ÕÕÖð¸ö×Ö·û½øÐбȽϣ¬²ÉÓõÄÊÇÿ¸ö×Ö·ûÔÚUnicode±àÂ뼯ÖеÄÊýÖµ¡£
7. ÔËËã·û+±È½ÏÌØÊ⣬Èç¹û¸ÃÔËËã·ûµÄÒ»¸öÔËËãÊýÊÇ×Ö·û´®£¬ÄÇôÁíÒ»¸öÔËËãÊý½«±»×ª»»Îª×Ö·û´®¡£µ±+ÓÃÓÚ×Ö·û´®ºÍÊý×Öʱ£¬²¢²»Ò»¶¨¾ßÓнáºÏÐÔ£º
s = 1 + 2 + “blind mice”; // Éú³É “3 blind mice”
t = “blind mice” + 1 + 2; // Éú³É “ blind mice12”
ÓÉÓÚ+ÔËËã·ûÊÇ´Ó×óµ½ÓÒÔËËãµÄ
Óï¾ä
1. for/in ¿ÉÒÔÓÃÀ´±éÀú¶ÔÏóµÄÊôÐÔ£¬È磺
for(variable in object) statement;
2. throwÓï¾ä
if(x<0) throw new Error(&ld
Ïà¹ØÎĵµ£º
ÔÚ¿ª·¢Öо³£»áÓÐÖ±½Ó¹Ø±ÕÒ³Ãæ²»µ¯³öÈκÎÌáʾµÄÐèÇó£¬ÔÚIE6ÖпÉÒÔÖ±½ÓÏóÏÂÃæÕâÑùд¾Í¿ÉÒÔÁË
<mce:script language=javascript><!--
window.opener=null
window.close()
// --></mce:script>
Õâ¸öÎÊÌâÔÚIE7ÖÐÔòÓпÉÄÜÊdzöÓÚijÖÖ°²È«¿¼ÂÇ£¨ÒòΪÔÚMSä¯ÀÀÆ÷µÄ¾ºÕù¶ÔÊÖFFÖУ¬ÊDz»Äܹرշ ......
옃주
<div id=demo style="overflow:hidden; width:128px; height:300px;">
<div id=demo1>
<img src="/gfjs.gif"><br><img src="/bxtt.gif"><br><img src="/bzjd.gif"><br>
<img src="/gfjs.gif"><br><img src="/bxtt.gif"><br><img ......
Ê×ÏÈ£¬ÔÚ¸÷¸öä¯ÀÀÆ÷ÖУ¬¶Ïµãµ÷ÊÔÖ§³ÖµÄ×îºÃµÄµ±È»ÊÇFirefox£¬Firefox²»½ö¿ÉÒÔʹÓÃFirebugµ÷ÊÔÒ³Ãæjs½Å±¾£¬»¹¿ÉÒÔÓø߼¶µ÷ÊÔ¹¤¾ßÀýÈçJavaScript Debugger (Venkman) À´µ÷ÊÔFirefoxÀ©Õ¹ÀïµÄjs¡£³ý´ËÖ®Í⣬Firefox»¹Ö§³ÖһЩ¸üΪ¸ß¼¶µÄ¶Ïµãµ÷ÊÔ¡¢±äÁ¿¼àÊÓ¹¦ÄÜ¡£
ÆäËûä¯ÀÀÆ÷ÀOpera¡¢ChromeºÍSafariµÄµ÷ÊÔ¹¦ÄÜÒ²±È½ÏºÃÓᣠ......
if (elename.equalsIgnoreCase("back") || elename.equalsIgnoreCase("1"))
return "<a href=\"javascript:window.history.back()\">ºóÍË</a>";
&nbs ......