如果...其他快速问题 [英] IF...Else Quick Question
问题描述
我很惊讶地发现Else if在下面的代码位中不需要。
显然是如果和Else if和Else if可互换使用。如果我错了，请纠正我，但它会出现B $ b，Else只是一种风格选择。
for（int i = 1; i< = 100; i ++）
{
如果（i == 3）
继续;
如果（i == 5）
休息;
Console.WriteLine（i）;
}
//编译得很好，我可以使用这个或else if告诉没有区别在第二个if
声明中。
提前致谢，
杰克
-
--------------------------------- --- - -
发布于NewsLeecher v3.9 Beta 5
Web @ http://www.newsleecher.com/?usenet
------------------- ----- - --- - -
" Arcticool" < ar ******* @ hotmail.comwrote：
显然是如果和Else if和Else if可互换使用。
在你的例子中它是相同的，因为继续;无论如何都将跳回到回路的顶部
，所以第二个if不会被处理。
但是，一般来说，它们并不相同。考虑：
int i = 5;
if（i <= 5）Console.WriteLine（小于或等于5）;
if（i == 5）Console.WriteLine（" equals 5"）;
这将打印两行文本，因为每个文本都是如果"处理
独立。
如果你添加else到第二行，然后第二条消息将永远不会打印出来，因为每当第二个条件为真时，第一个条件为真，因为
井，*和*第二个条件仅在else - case中执行，当
时，第一个不是。
Eq。
ar*******@hotmail.com 写道：
< blockquote class =post_quotes>
我很惊讶地发现Else if在下面的代码位中不需要。
显然是如果和Else if和Else if可互换使用。如果我错了，请纠正我，但它会出现B $ b，Else只是一种风格选择。
for（int i = 1; i< = 100; i ++）
{
如果（i == 3）
继续;
如果（i == 5）
休息;
Console.WriteLine（i）;
}
//编译得很好，我可以使用这个或else if告诉没有区别在第二个if
声明中。
提前致谢，
Jack
仅在跳过第二个if或者条件的情况下
不包括没有差异的第一个条件。
当你使用时继续跳过一些代码，它相当于
这段代码：
for（int i = 1; i <= 100; i ++）{
if（i == 3）{
//什么都不做
}否则{
如果（i == 5）{
休息;
}
Console.WriteLine（i ）;
}
}
请注意，如果不存在，则不存在任何其他构造。它只是一个包含if的其他
。当你这样写的时候：
if（something）{
...
}否则if（something）{< br $> b $ b ...
}
实际上是：
如果（某事）{
...
}否则{
if（something）{
...
}
}
-
G？跑Andersson
_____
http://www.guffa.com
ar*******@hotmail.com 写道：
我很惊讶地发现Else if在下面的代码位中不需要。
显然是如果和Else if和Else if可互换使用。如果我错了，请纠正我，但它会出现B $ b，Else只是一种风格选择。
for（int i = 1; i< = 100; i ++）
{
如果（i == 3）
继续;
如果（i == 5）
休息;
Console.WriteLine（i）;
}
//编译得很好，我可以使用这个或else if告诉没有区别在第二个if
语句中。
你在那里有两个独立且完整的if语句。
也可能是这样的。
如果（i == 3）
{
继续;
}
else
{
刹车; '除了3
}之外的其他任何东西}
---------
if（i == 3 ）
{
继续;
}
elseif（i 0&& i< 2）
{
刹车;
}
elseif（其他东西）
{
做点什么;
}
I was just surprised to find that "Else if" is not required in the code bit below.
Apparently "If" and "Else if" are used interchangeably. Please correct me if I''m wrong, but it
appears "Else" is just a stylistic choice.
for (int i = 1; i <= 100; i++)
{
if (i == 3)
continue;
if (i == 5)
break;
Console.WriteLine(i);
}
//Compiles just fine and I can tell no difference using this or "else if" in the second if
statement.
Thanks in advance,
Jack
--
--------------------------------- --- -- -
Posted with NewsLeecher v3.9 Beta 5
Web @ http://www.newsleecher.com/?usenet
------------------- ----- ---- -- -
"Arcticool" <ar*******@hotmail.comwrote:
Apparently "If" and "Else if" are used interchangeably.It''s the same in your example, because "continue;" will jump back to the top
of the loop anyway, so the second "if" won''t be processed.
In general, however, they are not the same. Consider:
int i = 5;
if (i <= 5) Console.WriteLine("less than or equal to 5");
if (i == 5) Console.WriteLine("equals 5");
This will print both lines of text, since each "if" is processed
independently.
If you add "else" to the second line, then the second message will never be
printed, because whenever the second condition is true, the first is true as
well, *and* the second condition is only performed in the "else"-case, when
the first was not.
Eq.
ar*******@hotmail.com wrote:I was just surprised to find that "Else if" is not required in the code bit below.
Apparently "If" and "Else if" are used interchangeably. Please correct me if I''m wrong, but it
appears "Else" is just a stylistic choice.
for (int i = 1; i <= 100; i++)
{
if (i == 3)
continue;
if (i == 5)
break;
Console.WriteLine(i);
}
//Compiles just fine and I can tell no difference using this or "else if" in the second if
statement.
Thanks in advance,
Jack
It''s only in situations where the second if is skipped or it''s condition
is exclusive of the first condition that there is no difference.
As you are using continue to skip some of the code, it''s equivalent to
this code:
for (int i = 1; i <= 100; i++) {
if (i == 3) {
// do nothing
} else {
if (i == 5) {
break;
}
Console.WriteLine(i);
}
}
Note that there doesn''t exist any "else if" construct. It''s just an else
containing an if. When you write like this:
if (something) {
...
} else if (something) {
...
}
it''s actually:
if (something) {
...
} else {
if (something) {
...
}
}
--
G?ran Andersson
_____
http://www.guffa.com
ar*******@hotmail.com wrote:I was just surprised to find that "Else if" is not required in the code bit below.
Apparently "If" and "Else if" are used interchangeably. Please correct me if I''m wrong, but it
appears "Else" is just a stylistic choice.
for (int i = 1; i <= 100; i++)
{
if (i == 3)
continue;
if (i == 5)
break;
Console.WriteLine(i);
}
//Compiles just fine and I can tell no difference using this or "else if" in the second if
statement.You got two independent and complete if statements up there above there.
It could be something like this too.
if (i==3)
{
continue;
}
else
{
brake; ''anything else but 3
}
---------
if (i == 3)
{
continue;
}
elseif ( i 0 && i < 2)
{
brake;
}
elseif ( something else )
{
do something;
}
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