3-3 字串

JavaScript ªº¦r¦ê¸ê®Æ«¬ºA¥i¥H¥Î¨Óªí¥Ü¤@¦C¤å¦r¤º®e¡C§Ú­Ì¥u­n§â¤å¦r¬A¦b¬Û²Åªº³æ¬A¸¹©ÎÂù¬A¸¹¸Ì¡A´N¥i¥H§Î¦¨¤@­Ó¦r¦ê¡CÂù¬A¸¹¥i¥H¥]§t¦b¬A¦b³æ¬A¸¹ªº¦r¦ê¸Ì¡A¦Ó³æ¬A¸¹¤]¥i¥H¥]§t¦b¬A¦bÂù¬A¸¹ªº¦r¦ê¸Ì¡C¤U¦C¬O¦r¦êªº½d¨Ò¡G

"This is a string" 'This is a string quoted by single quotes' "This is a string with 'single' quotes" 'This is a string with "double" quotes' "This another string with \"double\" quotes"
½Ðª`·N¦b¤W­z½d¨Ò¤¤ªº³Ì«á¤@­Ó¦r¦ê¥]§t¤FÂù¤Þ¸¹¡A¬°¤FÁ×±¼Âù¤Þ¸¹ªº­ì¨Ó¥Î³~¡]¼Ð¥Ü¦r¦êªº¶}©l©Mµ²§ô¡^¡A§Ú­Ì­n¦bÂù¤Þ¸¹«e¥[¤W¤Ï±×½u¡]\¡^¡C

JavaScript ªº¦r¦êª«¥ó¨ã³Æ¤F³\¦h¤èªk¡A³o¨Ç¤èªk¥i¹ï¦r¦ê¥»¨­¶i¦æ¦UºØ­×§ï©Î­pºâ¡A©Ò³y¦¨ªº®ÄªG¥i¦C¥X¦p¤U¡G

Example¡]string01.htm¡^¡G

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­ì©lÀÉ¡]string01.htm¡^¡G¡]¦Ç¦â°Ï°ì«ö¨â¤U§Y¥i«þ¨©¡^
<html>
<head>
<meta HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=big5">
</head>

<body>
<h2 align=center>¦r¦êª«¥óªº¤èªk»P©Ê½è</h2>
<hr>

<script>
myStr = "Tang Poem: ¦h±¡«o¦üÁ`µL±¡¡A°ßı¾ê«e¯º¤£¦¨¡C";
document.write("­ì¦r¦ê¡GmyStr = " + myStr + "<br>");
document.write("¦r¦êªø«×¡GmyStr.length = " + myStr.length + "<br>");
document.write("¼W¤j¦r«¬¡GmyStr.big() = " + myStr.big() + "<br>");
document.write("´î¤p¦r«¬¡GmyStr.small() = " + myStr.small() + "<br>");
document.write("°{Ã{¦r¦ê¡GmyStr.blink() = " + myStr.blink() + "<br>");
document.write("ÅܶÂÅé¡GmyStr.bold() = " + myStr.bold() + "<br>");
document.write("Åܱ×Åé¡GmyStr.italics() = " + myStr.italics() + "<br>");
document.write("Åܵ¥¼e¦rÅé¡GmyStr.fixed() = " + myStr.fixed() + "<br>");
document.write("ºb±¼¦r¦ê¡GmyStr.strike() = " + myStr.strike() + "<br>");
document.write("ÅܤU¼Ð¡GmyStr.sub() = " + myStr.sub() + "<br>");
document.write("ÅܤW¼Ð¡GmyStr.sup() = " + myStr.sup() + "<br>");
document.write("³]©wÃC¦â¡GmyStr.fontcolor(\"salmon\") = " + myStr.fontcolor("salmon") + "<br>");
document.write("³]©w¦r«¬¤j¤p¡GmyStr.fontsize(5) = " + myStr.fontsize(5) + "<br>");
document.write("´«¦¨¤j¼g¦r¥À¡GmyStr.toUpperCase() = " + myStr.toUpperCase() + "<br>");
document.write("´«¦¨¤p¼g¦r¥À¡GmyStr.toLowerCase() = " + myStr.toLowerCase() + "<br>");
document.write("¦r¦ê¨Ã±Æ¡GmyStr.concat(\"·s¥[ªº\") = " + myStr.concat("·s¥[ªº") + "<br>");
document.write("©â¥X¦r¤¸¡GmyStr.charAt(13) = " + myStr.charAt(13) + "<br>");
document.write("©â¥X Unicode ¦r¤¸¡GmyStr.charCodeAt(13) = " + myStr.charCodeAt(13) + "<br>");
document.write("©â¥X¤l¦r¦ê¡GmyStr.substr(13, 5) = " + myStr.substr(13, 5) + "<br>");
document.write("©â¥X¤l¦r¦ê¡GmyStr.substring(13, 15) = " + myStr.substring(13, 15) + "<br>");
document.write("´M§ä¤l¦r¦ê¡GmyStr.indexOf(\"±¡\") = " + myStr.indexOf("±¡") + "<br>");
document.write("´M§ä¤l¦r¦ê¡GmyStr.lastIndexOf(\"±¡\") = " + myStr.lastIndexOf("±¡") + "<br>");
</script>

<hr>
</body>
</html>

­nª`·Nªº¬O¡A¦b°õ¦æª«¥óªº¤èªk®É¡A¿é¤J¤Þ¼Æ¥i¦³¥iµL¡A¦ý¬A¸¹¤@©w­n¦³¡A¦¹­n¨D©M JavaScript ªº¨ç¼Æ¬O¤@­Pªº¡C¦r¦êª«¥ó±`¥Îªº¤èªk¥i¥H¦Cªí»¡©ú¦p¤U¡G

ª«¥ó©Ê½è©Î¤èªk»¡©úµ¥®ÄªºHTML¼ÐÅÒ
Stringlength¶Ç¦^¦r¦êªºªø«×
big()¼W¤j¦r¦êªº¦r«¬<big>...</big>
small()´î¤p¦r¦êªº¦r«¬<small>...</small>
blink()°{Ã{¦r¦ê¡]¦¹¤èªk¥u¾A¥Î©ó Netscape ÂsÄý¾¹¡A¤£¾A¥Î©ó IE ÂsÄý¾¹¡^<blink>...</blink>
bold()ÅܶÂÅé<b>...</b>
italics()Åܱ×Åé<i>...</i>
fixed()Åܵ¥¼e¦rÅé<tt>...</tt>
strike()ºb±¼¦r¦ê<strike>...</strike>
sub()ÅܤU¼Ð<sub>...</sub>
sup()ÅܤW¼Ð<sup>...</sup>
fontcolor()³]©w¦r¦êªºÃC¦â<font color=...>...</font>
fontsize()³]©w¦r¦êªº¦r«¬¤j¤p<font size=...>...</font>
toUpperCase()´«¦¨¤j¼g¦r¥À
toLowerCase()´«¦¨¤p¼g¦r¥À
concat()¦r¦ê¨Ã±Æ¡]µ¥®Ä©ó¨Ï¥Î¥[¸¹¡^
charAt(n)©â¥X²Ä n ­Ó¦r¤¸¡]n=0 ¥Nªí²Ä¤@­Ó¦r¤¸¡^
charCodeAt(n)©â¥X²Ä n ­Ó¦r¤¸¡]n=0 ¥Nªí²Ä¤@­Ó¦r¤¸¡^¡A¨ÃÂà´«¦¨ Unicode
substr(m, n)¶Ç¦^¤@­Ó¦r¦ê¡A±q¦ì¸m m ¶}©l¡A¥Bªø«×¬° n
substring(m, n)¶Ç¦^¤@­Ó¦r¦ê¡A±q¦ì¸m m ¶}©l¡Aµ²§ô©ó¦ì¸m n-1
indexOf(str)´M§ä¤l¦r¦ê str ¦b­ì¦r¦êªº²Ä¤@¦¸¥X²{¦ì¸m
lastIndexOf(str)´M§ä¤l¦r¦ê str ¦b­ì¦r¦êªº³Ì«á¤@¦¸¥X²{¦ì¸m

Hint
½Ð¯S§Oª`·N substr(m, n) ©M substring(m, n) ¦b¥\¯à¤Wªº®t²§¡C¦pªG text = "§ÚÄ@¬O¤d¸U±ø¦¿ªe"¡A«h
  • text.substr(3,5)·|¶Ç¦^ "¤d¸U±ø¦¿ªe"¡]²Ä3­Ó¦r¤¸¶}©l¡A¨ú5­Ó¦r¤¸¡^
  • text.substring(3,5)·|¶Ç¦^ "¤d¸U"¡]²Ä3­Ó¦r¤¸¶}©l¡A²Ä4­Ó¦r¤¸µ²§ô¡^

¦b¤Wªí¤¤¡A¦³Ãö©ó¦r¦êªº¤ñ¹ï¡A¥u´£¨ì¤F indexOf() ©M lastIndexOf() ¨â­Ó¤èªk¡A¨Æ¹ê¤W JavaScript ¹ï©ó¦r¦êªº¤ñ¹ï©M¥N´«¦³³\¦h±j¤jªº¥\¯à¡A¨Ò¦p search¡Bmatch¡Breplace µ¥¨ç¼Æ¡A³o¨Ç¥\¯à²ÎºÙ¡u³q¥Îªí¥Üªk¡v¡A±N·|¦b¨ä«á³¹¸`¥J²Ó¤¶²Ð¡C

¦³®É­Ô§Ú­Ì¤]¥i¥H±N¦r¦ê¬Ý¦¨¬O JavaScript ¤¤ªº«ü¥O¨Ó°õ¦æ¤§¡A³o®É­Ô©Ò¥Î¨ìªº¬ÛÃö«ü¥O¬O eval()¡A¦¹«ü¥O¯S§O¾A¥Î©ó¡u¨Ï¥Î°j°é³Ð³yÅܼơv¡A½Ð¨£¤U¦C½d¨Ò¡G

Example¡]eval01.htm¡^¡G

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­ì©lÀÉ¡]eval01.htm¡^¡G¡]¦Ç¦â°Ï°ì«ö¨â¤U§Y¥i«þ¨©¡^
<html>
<head>
<meta HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=big5">
</head>

<body>
<h2 align=center>¦p¦ó¨Ï¥Î eval()</h2>
<hr>

<script>
for (i=1; i<=3; i++){
	command = "x" + i + "=" + i*i*i;
	eval(command);
}
document.write("x1 = " + x1 + "<br>");
document.write("x2 = " + x2 + "<br>");
document.write("x3 = " + x3 + "<br>");
</script>

<hr>
</body>
</html>

¦b¤W­z½d¨Ò¤¤¡A§Ú­Ì§â JavaScript ­n°õ¦æªº©R¥O¦¬¶°¦b¦r¦êÅÜ¼Æ command¡AµM«á¦A¥Î eval «ü¥O¨Ó "°õ¦æ" ³o­Ó¦r¦ê¡A´N¥i¥H³Ð³y¥X¤T­ÓÅÜ¼Æ x1¡Bx2 ©M x3¡C

JavaScript ÁÙ¦³¤@¨Ç¤º«Ø©Î¨Ï¥ÎªÌ¦Û³Ðªºª«¥ó¡A¹ï©ó³o¨Çª«¥ó¡A§Ú­Ì¥i¥H¨Ï¥Î toString() ¨ÓÂà´«¦¨¦r¦êªí¥Ü¡A¨Ò¦p¡G

Example¡]toString01.htm¡^¡G

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­ì©lÀÉ¡]toString01.htm¡^¡G¡]¦Ç¦â°Ï°ì«ö¨â¤U§Y¥i«þ¨©¡^
<html>
<head>
<meta HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=big5">
</head>

<body>
<h2 align=center>¦p¦ó¨Ï¥Î toString()</h2>
<hr>

<script>
x = "This is a string";
document.write("¦r¦ê¡G" + x.toString()+"<br>");
x = new Date();
document.write("¤é´Á¡G" + x.toString()+"<br>");
x = ["Mon", "Tue", "Wed"];
document.write("°}¦C¡G" + x.toString()+"<br>");
function square(n){
	return(n*n);
}
document.write("¨ç¼Æ¡G" + square.toString()+"<br>");
student = new Object();
student.name = "Timmy";
student.age = "25";
student.phone = "575-1114";
document.write("¦Û­qª«¥ó¡G" + student.toString()+"<br>");
</script>

<hr>
</body>
</html>

¥Ñ¤W¨Ò¥i¥H¬Ý¥X¡AtoString() ªº¦æ¬°µøª«¥ó«¬ºA¦Ó©w¡A¥i¦Cªí»¡©ú¦p¤U¡G

ª«¥ótoString() ªºµ²ªG
Array¡]°}¦C¡^±N Array ªº¤¸¯ÀÂà´«¬°¦r¦ê¡A§Î¦¨¥H³r¸¹¦ê³s°_¨Óªºµ²ªG¡A¦¹µ²ªG »P Array.toString() ©M Array.join() ±o¨ìªºµ²ªG¬Û¦P
Boolean¡]¥¬ªL¡^¦pªG¥¬ªL­È¬° True¡A·|¶Ç¦^ "true"¡F§_«h·|¶Ç¦^ "false"
Date¡]¤é´Á¡^¶Ç¦^Åã¥Ü¤é´Áªº¤å¦r§Î¦¡
Error¡]¿ù»~¡^¶Ç¦^¥]§t¿ù»~°T®§ªº¦r¦ê
Function¡]¨ç¼Æ¡^¶Ç¦^¨ç¼Æªº©w¸q
Number¡]¼Æ¦r¡^¶Ç¦^¼Æ¦rªº¤å¦rªí¥Üªk
String¡]¦r¦ê¡^¶Ç¦^ String ª«¥óªº­È
¦Û­qª«¥ó¶Ç¦^ "[object Object]"

¦¹¥~¡A­Y­n±N¦r¦êÂন¼Æ­È¡A¥i¥Î parseInt() ©Î¬O parseFloat() ³o¨â­Ó¨ç¼Æ¡A»¡©ú¦p¤U¡G

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