JavaScript?? String ??? ??? ???

String ??? ??? ???

??: ??? ???? ??. ?: var len = strObj.length
toLowerCase(): ???? ??? ?? ???? ?????. ?: strObj.toLowerCase()
toUpperCase(): ???? ??? ?? ???? ?????. ?: strObj.toUpperCase()

<!DOCTYPE HTML>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <title>php.cn</title>
        <script>
           var str="ASDfgh";
           document.write(str.length+"<br/>");
           document.write(str.toLowerCase()+"<br/>");
           document.write(str.toUpperCase()+"<br/>");
        </script>
    </head>
    <body>
    </body>
</html>

charAt(index)

??: ??? ?? ??? ?? ??? ?????. ?? ? ??? ? ???? ?????.
??: strObj.charAt(index)
????: index? ??? ??? ????, ???? ???? ??? ?????. ??? ?? .

???

indexOf()

??: ?? ????? ?? ???? ??? ?? ?????(?? ??? ???? ??????). ?? ? ??? -1? ?????.
??: strObj.indexOf(substr)
????: substr? ?? ?? ???? ?????.

<!DOCTYPE HTML>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <title>php.cn</title>
        <script>
           var str="Hello JavaScript";
            for(var i=0;i<str.length;i++){
                document.write(str.charAt(i)+"<br/>");
            }
        </script>
    </head>
    <body>
    </body>
</html>

lastIndexOf()

?? : ?? ????? ????? ???? ?? ?? ???? ?????. ?? ? ??? -1? ?????.
??: strObj.lastIndexOf(substr)
????: substr? ?? ?? ???? ?????.

???

substr()

??: ?? ????? ?? ???? ?????.
??: strObj.substr(startIndex [, length])
??: ?? ?? startIndex?? ???? ?? ??? ?????.
????:

startIndex? ??? ?? ??? ??? ?????.
??? ?????? ? ?? ??? ?????. ???? ?? ??? ?????.

???

substring()

??: ?? ????? ?? ???? ?????.
??: strObj.substring(startIndex [, endIndex])
??: startIndex?? ? ??? ???? ?? ??? ?? ?????. endIndex ??? ?? ??.
????:

startIndex: ?? ??? ?? ?????.
endIndex: ?? ??, ? ??? ?? ?????. ???? ????? ??? ?? ??? ?????.

??: ? ?? ????? ???? substr()? substring()? ??? ?????.

??: substring()?? ??? ???? startIndex? ??? ???? endIndex? ??? ???? ????.

<!DOCTYPE HTML>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <title>php.cn</title>
        <script>
           var str="Hello JavaScript";
           document.write(str.indexOf("J")+"<br/>");   
           document.write(str.indexOf("S")+"<br/>");   
           document.write(str.indexOf("s")+"<br/>");   
        </script>
    </head>
    <body>
    </body>
</html>

split(): ???? ??? ??

??: ???? ?? ????? ????. ??? ?????.
??: strObj.split(?? ??)
????: ????? ?? ??? ??????. ??? ?? ??? ???? ???? ????? ????.

??? ?? ??? ???? ??? Hello JavaScript
? ?? Hello, JavaScript? ????. ? ?

????

???? ??

??? ??

<!DOCTYPE HTML> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>php.cn</title> <script> var str="ASDfgh"; document.write(str.length+"<br/>"); document.write(str.toLowerCase()+"<br/>"); document.write(str.toUpperCase()+"<br/>"); </script> </head> <body> </body> </html>

?????? ???

????