Addition of two character literals in c++

Question

When I write the following code the output is 110. Can anyone tell me why I get that value?

#include<iostream>
int main()
{
    std::cout << '9' + '5';
    return 0;
}

You are passing 9 and 5 as a string so it is giving result accordingly — Exterminator, Oct 04 '18 at 13:17
Possible duplicate of [Sum of two chars in C/C++](https://stackoverflow.com/questions/19471235/sum-of-two-chars-in-c-c) — dtell, Oct 04 '18 at 13:19
@Slava How so? All I did was make the words express what the OP was doing — NathanOliver, Oct 04 '18 at 13:21
@NathanOliver but the problem is OP wanted to do different thing - he wanted to concatenate 2 strings and subject clearly showed that. You reverse engineered his subject so it is not clear what OP really wanted. — Slava, Oct 04 '18 at 13:22
@Slava Probably, but the OP never said that and nothing I removed alluded to that. If that is what the OP wants you should ask them to clarify that. — NathanOliver, Oct 04 '18 at 13:23
@NathanOliver "but the OP never said that" he actually did by the subject and you removed that. — Slava, Oct 04 '18 at 13:23
@Slava If you want to fix it and add words to the OP's mouth go ahead. I'm not going to do that. — NathanOliver, Oct 04 '18 at 13:24
I think OP can do that by himself. @krishna if you wanted to concatenate 2 strings you should revert the subject and clearly say that in the question itself. — Slava, Oct 04 '18 at 13:27

Some programmer dude · Accepted Answer · 2018-10-04T13:19:28.070

4

With ASCII encoding the values of '9' and '5' is 57 and 53 (respectively).

57 + 53 is equal to 110.

What you're adding is the encoded values of the characters, not their digits.

And you get the output 110 (instead of the ASCII character 'n' which have the value 110) because the addition causes the characters to be promoted to int values and the result is an int value that is not converted to a char.

edited Oct 04 '18 at 13:19

answered Oct 04 '18 at 13:14

Some programmer dude

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"instead of the ASCII character 'n'" I think OP expects to get string "95" as a result, not character – Slava Oct 04 '18 at 13:18
@Slava I know, but I mean that `110` is `'n'`. – Some programmer dude Oct 04 '18 at 13:20
I see, but I got is as OP wanted to get `n` and he is asking why 110 instead. – Slava Oct 04 '18 at 13:25

score 1 · Answer 2 · answered Oct 04 '18 at 13:15

According to this, the value of 9 is 57, and the value of 5 is 53. 57 + 53 is 110. You're adding those chars, so they get promoted to int, and if you pass an int like this, it gets printed as an int.

What you probably wanted is

std::cout << '9' << '5';

to print 95. Or

std::cout << 9 + 5;

to print 14.

sagi · Answer 3 · 2018-10-04T13:48:04.103

0

The ASCII value of 9 is 57 and of 5 is 53. So 57 + 53 equals 110.

There is no addition for characters, you're adding their ascii value . If you will cast the result to char, the result should be n .

edited Oct 04 '18 at 13:48

answered Oct 04 '18 at 13:13

sagi

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KostasRim · Answer 4 · 2018-10-04T14:25:07.770

0

That's because char's are represented in ASCII(usually as per suggested on the comments).

Literal '9' is 57 and literal '5' is 53. Thus their sum is 110 which is the literal 'm'.

edited Oct 04 '18 at 14:25

answered Oct 04 '18 at 13:13

KostasRim

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`char`s do not have to be ASCII. – Lightness Races in Orbit Oct 04 '18 at 14:18
@LightnessRacesinOrbit I am unaware of an implementation that doesn't. Although, I am really curious what the standard says – KostasRim Oct 04 '18 at 14:22
@LightnessRacesinOrbit Thank you for that link! – KostasRim Oct 04 '18 at 14:24

score 0 · Answer 5 · answered Oct 04 '18 at 13:15

0

The is no char operator+(char, char), but there is int operator+(int, int). Hence it converts '9' and '5' to ints 57 and 53 respectively first and then does the addition, which result is int 110.

answered Oct 04 '18 at 13:15

Maxim Egorushkin

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score 0 · Answer 6 · answered Oct 04 '18 at 14:14

Based on the original title, it's possible that the OP's intent was to concatenate two string numbers together. If so, this should achieve that.

#include<iostream>
#include<string>
int main()
{
    std::cout << std::string("9") + std::string("5");
    return 0;
}

score 0 · Answer 7 · answered Oct 04 '18 at 16:28

0

With ASCII encoding the values of '9' and '5' is 57 and 53.

57 + 53 is equal to 110.

And the program is returning this value.

If you want program to return the addition of 9 and 5 the you have to write following syntax :-

cout<<9+5;

answered Oct 04 '18 at 16:28

Pranjal Tripathi

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Addition of two character literals in c++

7 Answers7