Thread: Please Explain me few terms that i have listed in here.

  1. #1
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    Please Explain me few terms that i have listed in here.

    Hello,
    Kindly explain me the function of wchar_t ,size_t ,memcpy() i have read many times the community members using this but i never realised what they are for?If anybody could explain me the syntax and use of it or could link me to some page which explain's its usage i will be very thankful

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    Also explain me the function of realloc()

  3. #3
    C++まいる!Cをこわせ!
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    wchar_t is the data type for unicode, at least within Windows environment. If you don't know what unicode is, perhaps you should read up about it on wikipedia or such...
    size_t is a data type used by the C++ Standard Library. It's generally a "reserved" type returned by some functions and shouldn't be cast, if possible.
    memcpy is a function that copies n bytes of memory from one location to another. Generally avoided in C++ since it's more a C function.
    realloc takes an existing allocation from malloc and resizes it to the new specified size. If it can't expand the current memory block, it allocates a new region of the specified size, copies data over and frees the old one. Is not to be used with new/delete. Avoid if possible. Use only with malloc/free.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  4. #4
    Cat without Hat CornedBee's Avatar
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    wchar_t is the standard "wide character" data type. What that means depends on the compiler.
    size_t is primarily the result type of the sizeof operator. It is also used for various other size values in the CRT.
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
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