Welcome to ShenZhenJia Knowledge Sharing Community for programmer and developer-Open, Learning and Share
menu search
person
Welcome To Ask or Share your Answers For Others

Categories

If you have lets say a local int that is uninitialized, then its gets an undefined value but if you have a local char variable should that not have an undefined value as well? Of course 0 could be that undefined value, but i was wondering if char is any different, since all related info i find is about int and the program below just outputs 0 when the char variable is cast to an int. Im using GCC 4.7 with no flags.

int main()
{
char test1;
int test2;

std::cout<<test2; //garbage
std::cout<<std::endl;
std::cout<<(int)test1; //0
    return 0;
}
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
thumb_up_alt 0 like thumb_down_alt 0 dislike
557 views
Welcome To Ask or Share your Answers For Others

1 Answer

Uninitialised means really uninitialised. Just because you consistently get a particular value on your machine at a particular time, doesn't mean that will always be the case all the time on all machines.

You can verify that nothing is initialising your variable by dumping the assembly code for your function and inspecting it.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
thumb_up_alt 0 like thumb_down_alt 0 dislike
Welcome to ShenZhenJia Knowledge Sharing Community for programmer and developer-Open, Learning and Share
...