?????? ???

???? ??? ?? ???? ??? ?, DOM ??? ??? ??? ??? ?, ??? ??? ? ? JavaScript? ?? ?? ?? ????. JavaScript? ?? ??? ??? ??, ??? ???? ??, ?? ??? ?? ?? ?? ???? ??? ??? ?? ?? ? ??? ??? ?????.

??? ??

???? ???? ???? ?? ??? ????. ?? ??? ??? ??? ??? ??? ? ?? ?? ??? ???? ?? ????.
var myStr = "Hello, String!";
????? ?????? ???? ???? ??? ? ??? ???? ???? ??? ?? ???? ?? ??? ? ??? ?? ?????.
var myString = "Fluffy is a Pretty cat.';? ?? ?? ?????.
? ?? ??? ???? ???? ?? ??? ???? ????(?: ??? ?? ??? ??):

document.write("< img src='img/logo.jpg' height='30' width='100' alt='Logo'>");

??? ??

?? ?????. ? ?? ???? "??"??? "+"? ?????.

var longString = "? ?? " + "? ?? ? ??."

? ???? ?? ???? ???? "+= " ???:

var result = "";
result += "My name is Anders"
result += " and my age is 25";

???? ?? ??? ????? ??? ???? ???. ????? ?? "n"? ??????.

var verifyString = "??? " +
"question.nnSubmit ??? ?? ??? ???? ???????";
var verifyValue = verify(confirmString);

??? ??

?? ??? length? ???? ??? ??? ??? ? ????.

<!DOCTYPE html>
<html>
<head> 
<meta charset="utf-8"> 
<title>php中文網(wǎng)(php.cn)</title> 
</head>
<body>
<script>
var txt = "Hello World!";
document.write("<p>" + txt.length + "</p>");
var txt="what are you doing ?";
document.write("<p>" + txt.length + "</p>");
</script>
</body>
</html>

?? ??

JavaScript?? ???? ?????? ????? ?????.

? ??? ?? ?? JavaScript? ?? ??? ? ????.

?? ??? ???? ??? ?????? ??? ?? ????()? ???? "Vikings" ????? ????? ?????? ? ????.
"We are the ?? "Vikings" from the north."

????? ??? ???? ????????. . ????? ??? ?? ??? ??? ??? ?????.

????? ??()? ??????, ??, ??? ? ?? ?? ??? ??????? ? ??? ? ????. ?? ??? ????? ????? ??? ???? ?????? ? ?? ?? ??? ???? ????.

Code

Output

' ?????

" ????

\ ????

n ? ??

r ??? ??

t ?(?)

b ????? ??

f ? ?? ??

???? ??? ? ??

<!DOCTYPE html>
<html>
<head> 
<meta charset="utf-8"> 
<title>php中文網(wǎng)(php.cn)</title> 
</head>
<body>
<p id="demo"></p>
<script>
var x = "John";              // x是一個(gè)字符串
var y = new String("John");  // y是一個(gè)對象
document.getElementById("demo").innerHTML =typeof x + " " + typeof y;
</script>
</body>
</html>

??:

??? ??? ???? ????. ?? ???? ?? ? ????

??? ?? ? ???

"John"? ?? ?? ? ????? ??? ??? ??? ??? ???? ????.

?? ?? JavaScript ?? ? ???? ??? ? ????. JavaScript? ??? ? ??? ??? ? ?? ?? ??? ??? ? ?? ?????.

???? ??

||

??? ??

<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>php中文網(wǎng)(php.cn)</title> <script> var name = '小明'; var age = 20; var message = '你好, ' + name + ', 你今年' + age + '歲了!'; alert(message); </script> </head> <body> </body> </html>

?????? ???
????