CODEWITHSUNDEEP
c++charint
gabor aron
gabor aron

Reputation: 410

How can I convert char to int in c++ to get correct values of numbers?

I want to convert char to int in c++, I used char a1 and to convert (int)a1 but I got wrong values, for example: if a1 is '1' then 49 if a1 is '2' then 50 etc... Why is this? How can I resolve this?

Upvotes: 1

Views: 12231

Answers (4)

LogicalAnt
LogicalAnt

Reputation: 963

To get real value subtract the initial value like 

char x='1'; //ascii value=49
int xx=x-'0' //49-48==1

char a='C'; //67
char aa=a-'A' //67-65=2 means third char of Alphabet

or you can type cast to get exact value
Hope you get the idea.

Upvotes: 1

H. M. Tarek Ullah
H. M. Tarek Ullah

Reputation: 126

int atoi (const char * str) this function can be helpful in this regard. See the documentation here atoi() c++ reference

Upvotes: 3

VeminZ
VeminZ

Reputation: 78

It's because (int)a converts just type but not the value. Literally, it says to compiler 'treat value of a as an int value' which in case of '1' returns its ASCII code 49. To translate the actual value you can use:

// num == 49 - 48; 
int num = (int)a - (int)'0';

Upvotes: 1

Ben Steffan
Ben Steffan

Reputation: 1125

This happens because char values are usually encoded in ASCII. This means that '1', for example, is represented by the numerical value 49. To have an alphabetical conversion (i.e. convert '1' to 1), take a look at std::to_string, or, if you're working with c-style strings, at itoa.

Upvotes: 0

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