Initilizing global array to all zeroes

This is a discussion on Initilizing global array to all zeroes within the C++ Programming forums, part of the General Programming Boards category; Hi, is it possible to inialize an array of integers(or chars or whatever) declared globally to all zeroes at compile ...

  1. #1
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    Initilizing global array to all zeroes

    Hi, is it possible to inialize an array of integers(or chars or whatever) declared globally to all zeroes at compile time?

    Ie. Can I write something like this int a[100] = {0} and be sure that all elements of 'a' will initially be zero when I execute my program?

    Thanks.

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    Interesting, why is this? I thought that this wasn't the case for local var's because C++ didn't want to force you to do that (inefficient), but why would they do so for globals?

  3. #3
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    Originally posted by roktsyntst
    Interesting, why is this? I thought that this wasn't the case for local var's because C++ didn't want to force you to do that (inefficient), but why would they do so for globals?
    I guess because globals have their contents set at compile time so there wouldnt be any efficiency hit...the memory from the executable would just be mapped as is from the file

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    >>I guess because globals have their contents set at compile time
    Or runtime.

    3.6.2 Initialization of non-local objects [basic.start.init]
    The storage for objects with static storage duration shall be zero-initialized before any other initialization takes place...Objects of POD types (...) shall be initialized before any dynamic initialization takes place.

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