指针只是另一个变量，用来保存内存位置的地址(通常是另一个变量的内存地址)。

指针只是另一个变量，它通常包含另一个变量的内存地址。指针是一个变量，它也有一个内存地址。

A pointer, like any other variable in C, is fundamentally a collection of bits which may be represented by one or more concatenated unsigned char values (as with any other type of cariable, sizeof(some_variable) will indicate the number of unsigned char values). What makes a pointer different from other variables is that a C compiler will interpret the bits in a pointer as identifying, somehow, a place where a variable may be stored. In C, unlike some other languages, it is possible to request space for multiple variables, and then convert a pointer to any value in that set into a pointer to any other variable within that set.

Many compilers implement pointers by using their bits store actual machine addresses, but that is not the only possible implementation. An implementation could keep one array--not accessible to user code--listing the hardware address and allocated size of all of the memory objects (sets of variables) which a program was using, and have each pointer contain an index into an array along with an offset from that index. Such a design would allow a system to not only restrict code to only operating upon memory that it owned, but also ensure that a pointer to one memory item could not be accidentally converted into a pointer to another memory item (in a system that uses hardware addresses, if foo and bar are arrays of 10 items that are stored consecutively in memory, a pointer to the "eleventh" item of foo might instead point to the first item of bar, but in a system where each "pointer" is an object ID and an offset, the system could trap if code tried to index a pointer to foo beyond its allocated range). It would also be possible for such a system to eliminate memory-fragmentation problems, since the physical addresses associated with any pointers could be moved around.

Note that while pointers are somewhat abstract, they're not quite abstract enough to allow a fully-standards-compliant C compiler to implement a garbage collector. The C compiler specifies that every variable, including pointers, is represented as a sequence of unsigned char values. Given any variable, one can decompose it into a sequence of numbers and later convert that sequence of numbers back into a variable of the original type. Consequently, it would be possible for a program to calloc some storage (receiving a pointer to it), store something there, decompose the pointer into a series of bytes, display those on the screen, and then erase all reference to them. If the program then accepted some numbers from the keyboard, reconstituted those to a pointer, and then tried to read data from that pointer, and if user entered the same numbers that the program had earlier displayed, the program would be required to output the data that had been stored in the calloc'ed memory. Since there is no conceivable way the computer could know whether the user had made a copy of the numbers that were displayed, there would be no conceivable may the computer could know whether the aforementioned memory might ever be accessed in future.

Come to think about it, I think it's a matter of semantics. I don't think the author is right, since the C standard refers to a pointer as holding an address to the referenced object as others have already mentioned here. However, address!=memory address. An address can be really anything as per C standard although it will eventually lead to a memory address, the pointer itself can be an id, an offset + selector (x86), really anything as long as it can describe (after mapping) any memory address in the addressable space.

马克·贝西(Mark Bessey)已经说过了，但这一点需要再次强调，直到人们理解为止。

指针与变量的关系比与文字3的关系更大。

指针是一个值(地址)和类型(带有其他属性，如只读)的元组。类型(以及附加参数(如果有的话)可以进一步定义或限制上下文;如。__far ptr， __near ptr:地址的上下文是什么:堆栈，堆，线性地址，某处的偏移量，物理内存或其他。

正是type的属性使得指针算术与整数算术略有不同。

指针不是变量的反例太多了，不容忽视

fopen返回FILE指针。(变量在哪里) 堆栈指针或帧指针通常是不可寻址的寄存器 *(int *)0x1231330 = 13;——将任意整数值转换为pointer_of_integer类型，并在不引入变量的情况下写入/读取整数值

在c程序的生命周期中，会有许多其他没有地址的临时指针实例——因此它们不是变量，而是带有编译时相关类型的表达式/值。

指针是表示内存位置的抽象。请注意，这句话并没有说把指针当作内存地址是错误的，它只是说它“通常会导致悲伤”。换句话说，它会让你产生错误的期望。

The most likely source of grief is certainly pointer arithmetic, which is actually one of C's strengths. If a pointer was an address, you'd expect pointer arithmetic to be address arithmetic; but it's not. For example, adding 10 to an address should give you an address that is larger by 10 addressing units; but adding 10 to a pointer increments it by 10 times the size of the kind of object it points to (and not even the actual size, but rounded up to an alignment boundary). With an int * on an ordinary architecture with 32-bit integers, adding 10 to it would increment it by 40 addressing units (bytes). Experienced C programmers are aware of this and put it to all kinds of good uses, but your author is evidently no fan of sloppy metaphors.

There's the additional question of how the contents of the pointer represent the memory location: As many of the answers have explained, an address is not always an int (or long). In some architectures an address is a "segment" plus an offset. A pointer might even contain just the offset into the current segment ("near" pointer), which by itself is not a unique memory address. And the pointer contents might have only an indirect relationship to a memory address as the hardware understands it. But the author of the quote cited doesn't even mention representation, so I think it was conceptual equivalence, rather than representation, that they had in mind.