How to convert char to integer in C?

c char int
Cute picture Cute · May 15, 2009 · Viewed 502k times · Source

Possible Duplicates:
How to convert a single char into an int
Character to integer in C

Can any body tell me how to convert a char to int?

char c[]={'1',':','3'};

int i=int(c[0]);

printf("%d",i);

When I try this it gives 49.

Answer

Paul Tomblin picture Paul Tomblin · May 15, 2009

In the old days, when we could assume that most computers used ASCII, we would just do

int i = c[0] - '0';

But in these days of Unicode, it's not a good idea. It was never a good idea if your code had to run on a non-ASCII computer.

Edit: Although it looks hackish, evidently it is guaranteed by the standard to work. Thanks @Earwicker.

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