如何确定int是否没有值 [英] How to find out if an int has no value
问题描述
在我想到这些问题之前我已经尝试过这个问题了。
这个问题。这是一件很简单的事情，但它让我疯了！
是否可以检查int（或任何其他类型）是否没有价值。
类似于：
int i;
...
...
...
if（i == NULL）{
......
}
我知道这不起作用，我知道NULL是一个指针。有没有办法
这可以吗？
TIA。
Richard< ; RI ************** @ hotmail.com>潦草地写着以下内容：在我想到这些问题之前，我已经尝试过这个问题了。这是一件很简单的事情，但它让我疯了！
是否有可能检查int（或任何其他类型）是否没有价值。
类似于：
标量类型（如整数）总是有值。因此你的问题
没有意义。
-
/ - Joona Palaste（pa ***** @ cc.helsinki.fi）-------------芬兰-------- \
\-- http://www.helsinki.fi/~palaste ------------ ---------规则！ -------- /
人类中的孤雌生殖将导致建立一个新的宗教信仰。
- John Nordberg
Joona I Palaste< pa ***** @ cc.helsinki.fi>写在
新闻：ci ********** @ oravannahka.helsinki.fi：
Richard< ri **** **********@hotmail.com>潦草地写着以下内容：在我想到这个问题之前，我已经尝试过这个问题了。这是一件非常简单的事情，但它正在驱使我坚果！是否可以检查int（或任何其他类型）是否没有
值。类似于：
标量类型（如整数）总是有值。因此，你的
问题没有意义。
好吧，我应该更加特别。
我有这个：
typdef struct
{
int x;
int y;
}点;
//我现在想制作一个检查Point是否为空的函数
int pointEmpty （点p）
{
返回（p / * isEmpty * /？1：0）
}
我该怎么做？
TIA
>我真的我试着用这个问题来解决这个问题之前我试着打扰你们。它是如此简单，但它让我疯了！
是否有可能检查int（或任何其他类型）是否没有价值。
int永远不会有没有值。 C不像SQL那样整数
变量可以有null和整数值。 AC变量
可能有一个未初始化或未定义的值，在这种情况下它可能
有任何值，但这与变量无法区分
分配该值。它可能有某种陷阱值b / b值，这是不能测试的，因为如果你尝试程序终止。
指针可能有一个NULL值，这与没有
值不一样。
Gordon L. Burditt
I''ve really tried searching for this before I thought of bother you guys
with this question. It''s such a simple thing, but it''s driving me nuts!
Is it possible to check if an int (or any other type) has no value.
something like:
int i;
...
...
...
if (i==NULL){
......
}
I know this doesn''t work and I know NULL is a pointer. Is there any way
this can be done?
TIA.
Richard <ri**************@hotmail.com> scribbled the following:I''ve really tried searching for this before I thought of bother you guys
with this question. It''s such a simple thing, but it''s driving me nuts!
Is it possible to check if an int (or any other type) has no value.
something like:
Scalar types, such as ints, always have values. Therefore your question
does not make sense.
--
/-- Joona Palaste (pa*****@cc.helsinki.fi) ------------- Finland --------\
\-- http://www.helsinki.fi/~palaste --------------------- rules! --------/
"Parthenogenetic procreation in humans will result in the founding of a new
religion."
- John Nordberg
Joona I Palaste <pa*****@cc.helsinki.fi> wrote in
news:ci**********@oravannahka.helsinki.fi:
Richard <ri**************@hotmail.com> scribbled the following:I''ve really tried searching for this before I thought of bother you
guys with this question. It''s such a simple thing, but it''s driving
me nuts! Is it possible to check if an int (or any other type) has no
value. something like:
Scalar types, such as ints, always have values. Therefore your
question does not make sense.
Okay, than I should be more spesific.
I''ve got this:
typdef struct
{
int x;
int y;
} Point;
// I now want to make a function that checks if a Point is empty
int pointEmpty(Point p)
{
return (p /*isEmpty*/ ? 1 : 0)
}
How should I do that?
TIA
>I''ve really tried searching for this before I thought of bother you guyswith this question. It''s such a simple thing, but it''s driving me nuts!
Is it possible to check if an int (or any other type) has no value.
An int never has "no value". C is not like SQL where integer
variables can have null as well as integer values. A C variable
may have an uninitialized or undefined value, in which case it might
have any value, but this is not distinguishable from a variable
that is assigned that value. It might have some kind of trapping
value, which can''t be tested because if you try the program terminates.
Pointers may have a NULL value, which is not the same thing as "no
value".
Gordon L. Burditt
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