如果是其他格式 [英] If Else format

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问题描述

我O''Reilly的第90页Javascript权威指南第3版

有一个If / Else结构的例子:(删除了一些文字)


If(用户名!= null)

alert(Hello+用户名);

else {

username = prompt("你叫什么名字?);

alert(" Hello" + username);

}

我应该删除第一个" ;;"从第二行开始?


在我的测试中肯定会有更好的效果,但是我不知道这是否是书中的错误
,改变JavaScript的工作方式,或者浏览器中的一个缺陷




-

Steve Swift
http://www.swiftys.org.uk/swifty.html
http://www.ringers.org.uk

On page 90 of my O''Reilly "Javascript The definitive guide" 3rd edition
there is an example of an If/Else construct: (some text removed)

If (username != null)
alert("Hello " + username);
else {
username = prompt("What is your name?");
alert("Hello " + username);
}
Should I erase the first ";" from the second line?

It certainly works better in my tests that way, but I don''t know if this
is an error in the book, a change in the way JavaScript works, or a flaw
in my browser.

--
Steve Swift
http://www.swiftys.org.uk/swifty.html
http://www.ringers.org.uk

推荐答案



Steve Swift schreef:

Steve Swift schreef:

On我的O''Reilly的第90页Javascript权威指南第3版

有一个If / Else结构的例子:(删除了一些文字)


If(用户名!= null)

alert(Hello+用户名);

else {

username = prompt("你叫什么名字?);

alert(" Hello" + username);

}


我应该删除第一个" ;;"从第二行?
On page 90 of my O''Reilly "Javascript The definitive guide" 3rd edition
there is an example of an If/Else construct: (some text removed)

If (username != null)
alert("Hello " + username);
else {
username = prompt("What is your name?");
alert("Hello " + username);
}
Should I erase the first ";" from the second line?



编号为什么要这样?

这是命令的结束,为清楚起见,请使用分号。

No. Why should you?
It is the end of a command, and for clarities sake, use a semicolon.


>

它在我的测试中确实效果更好,但我不知道这是不是这个

本书中的错误,JavaScript工作方式的改变,或浏览器中的缺陷


>
It certainly works better in my tests that way, but I don''t know if this
is an error in the book, a change in the way JavaScript works, or a flaw
in my browser.



如果没有分号,它的效果如何?


Erwin Moller


-

============================

欧文Moller

现在放弃googlegroups的所有帖子。

为什么? http://improve-usenet.org/

= ===========================

How does it work better without the semicolon???

Erwin Moller

--
============================
Erwin Moller
Now dropping all postings from googlegroups.
Why? http://improve-usenet.org/
============================


9月19日,8:17 * am,Steve Swift< Steve.J.Sw ... @ gmail.comwrote:
On Sep 19, 8:17*am, Steve Swift <Steve.J.Sw...@gmail.comwrote:

在我的O''Reilly的第90页上Javascript权威指南 ;第3版

有一个If / Else结构的例子:(删除了一些文字)


If(用户名!= null)

* * alert(" Hello" + username);

else {

* * username = prompt("你叫什么名字?) ;

* * alert(你好+用户名);


}


我应该擦除第一个;从第二行开始?
On page 90 of my O''Reilly "Javascript The definitive guide" 3rd edition
there is an example of an If/Else construct: (some text removed)

If (username != null)
* *alert("Hello " + username);
else {
* *username = prompt("What is your name?");
* *alert("Hello " + username);

}

Should I erase the first ";" from the second line?



我用花括号包裹警告:


If(username!= null ){

alert(Hello+用户名);

} else {

username = prompt("你叫什么名字) ?");

alert(" Hello" + username);

}


-

Jorge。

I''d wrap that alert in curly braces:

If (username != null) {
alert("Hello " + username);
} else {
username = prompt("What is your name?");
alert("Hello " + username);
}

--
Jorge.


Steve Swiftaécrit:
Steve Swift a écrit :

我的O'的第90页'Reilly'Javascript权威指南第3版

有一个If / Else结构的例子:(删除了一些文字)


If(用户名!= null)
On page 90 of my O''Reilly "Javascript The definitive guide" 3rd edition
there is an example of an If/Else construct: (some text removed)

If (username != null)



no ...:if(blah)

(小写)

no ... : if ( blah )
(lowercase)


alert(" ;你好'+用户名};

else {

用户名=提示符("你叫什么名字?);

提醒(你好+用户名);

}


我应该删除第一个;"从第二行?
alert("Hello " + username);
else {
username = prompt("What is your name?");
alert("Hello " + username);
}
Should I erase the first ";" from the second line?



行尾的'';''在JS中是可选的

函数hello(){

if(typeof username ==''undefined''|| username == null)

username = prompt(''你的名字是什么?'')

alert (''你好''+用户名)

}


的工作原理如下:


函数你好( ){

if(typeof username ==''undefined''|| username == null){

username = prompt(''你叫什么名字?'' );

}

alert(''Hello''+用户名);

}


但是......正确编码要好得多。


-

sm

The '';'' in end of line is optional in JS
function hello() {
if(typeof username == ''undefined'' || username == null)
username = prompt(''What is your name?'')
alert(''Hello '' + username)
}

works as well as :

function hello() {
if(typeof username == ''undefined'' || username == null) {
username = prompt(''What is your name?'');
}
alert(''Hello '' + username);
}

But ... it''s much better to code correctly.

--
sm


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