Thread: size_t or unsigned int

Originally Posted by Dr.Paneas

I wanted to know what's the diff between unsigned int and size_t. To make my point clear to you, I 've already tried to sizeof both types, but they both returned the same size. One more thing, I've noticed that lot's of programmers tend to declare arryas in size_t. What's the catch and the whole meaning behind this ?

Thanks

NOTE: unsigned int is NOT always the same as size_t.

When you are using an system function that is supposed to use size_t always try to use size_t; only if it fails to work try "unsigned int" or "unsigned long int".

Tim S.

size_t is the type of the sizeof operator. It's used to measure the size of an entity in chars (usually bytes). It is supposed to be defined as an unsigned integer type (short (seems unlikely), standard, long, long long). To be portable you use size_t.

It's also a mnemonic showing that the variable is being used to represent a size, as opposed to some other unsigned entity. malloc takes a size_t. strlen and many other functions in string.h return or receive it.

The SIZE_MAX macro in stdint.h defines the maximum value of size_t, which is the maximum size in chars of any object since it's the maximum value that sizeof can return.

C++ also has the size_type type defined for its standard containers. Many people use size_t instead of size_type, but obviously they're not guaranteed to be the same.

To make my point clear to you, I 've already tried to sizeof both types, but they both returned the same size.

Try building a as a 64-bit application.