[英]What does char * mean
So...say I had a function like this... 所以...说我有这样的功能......
int function( const char *c )
{
//do something with the char *c here...
}
what does char *c
mean? char *c
是什么意思? I know about chars in general I think but I don't get what the * does...or how it changes the meaning. 我一般都知道chars,但我不知道*做了什么......或者它是如何改变意义的。
这意味着这是一个指向char类型数据的指针。
char *c
means that c is a pointer. char *c
表示c是指针。 The value that c points to is a character. c指向的值是一个字符。
So you can say char a = *c
. 所以你可以说
char a = *c
。
const
on the other hand in this example says that the value c points to cannot be changed. 另一方面,在这个例子中,
const
表示值c指向不能改变。 So you can say c = &a
, but you cannot say *c = 'x'
. 所以你可以说
c = &a
,但你不能说*c = 'x'
。 If you want a const pointer to a const character you would have to say const char* const c
. 如果你想要一个指向const字符的const指针,你必须说
const char* const c
。
This is a pointer to a character. 这是一个指向角色的指针。 You might want to read up about pointers in C, there are about a bazillion pages out there to help you do that.
你可能想要读一下C中的指针,那里有大量的页面可以帮助你做到这一点。 For example, http://boredzo.org/pointers/ .
例如, http://boredzo.org/pointers/ 。
Pointer to a char. 指向char的指针。 That is, it holds the address at which a char is located.
也就是说,它保存了char所在的地址。
Thats a pointer-to-char
. 这是一个
pointer-to-char
的pointer-to-char
。 Now that you know this, you should read this: 既然你知道这一点,你应该读到这个:
您可能需要阅读Const正确性页面以获得关于指针和const的好主意。
http://cslibrary.stanford.edu/ is the best resource that I have come across to learn about pointers in C . http://cslibrary.stanford.edu/是我学习C中指针的最佳资源。 Read all the pointer related pdfs and also watch the binky pointer video.
阅读所有与指针相关的pdf,并观看binky指针视频。
This is a pointer to a char
type. 这是一个指向
char
类型的指针。 For example, this function can take the address of a char and modify the char, or a copy of a pointer, which points to an string. 例如,此函数可以获取char的地址并修改char或指向字符串的指针的副本。 Here's what I mean:
这就是我的意思:
char c = 'a';
f( &c );
this passes the address of c
so that the function will be able to change the c
char. 这传递了
c
的地址,以便该函数能够更改c
char。
char* str = "some string";
f( str );
This passes "some string" to f
, but f
cannot modify str
. 这会将“some string”传递给
f
,但f
不能修改str
。
It's a really basic thing for c++, that higher-level languages (such as Java or Python) don't have. 对于c ++来说,这是一个非常基本的东西,高级语言(如Java或Python)没有。
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