What do single quotes do in C++ when used on multiple characters?

Single quotes in C++ are used to denote characters, not strings. When you use single quotes around multiple characters or strings, C++ compiler will treat it as a multi-character literal, which will be stored as an integer value, representing the combined ASCII values of those characters. In this article, we will learn all about single quotes in C++ and how they behave when used with multiple characters.

Single Quotes in C++

In C++, single quotes are used to represent a single character. For example, 'a' is a character literal representing the english alphabet 'a'. For each character, C++ assigns a unique integer value based on the ASCII table.

char singleChar = 'a';
cout << "Single character literal: " << singleChar << endl; // Output: a

Single Quotes with Multiple Characters

When you use single quotes with multiple characters, like 'abc', C++ treats it as a multi-character literal. And when you try to print it to console, you will get a random integer value, which is the combined ASCII values of those characters. Let's see an example:

Example

In the code, below we will use single quotes with multiple characters and print the result.

#include <iostream>
using namespace std;

int main() {
    cout << 'testing';
    return 0;
}

The output of the above code will be:

1953066599

Warnings/Errors:
main.cpp:5:13: warning: character constant too long for its type
    5 |     cout << 'testing';

As you can see, the output is not 'testing', but rather a random integer value (1953066599 in this case). Along with output, you might also see a warning from the compiler saying "character constant too long for its type".

Why Integer Value For Multi-Character Literal?

When you use single quotes with multiple characters, C++ treats it as a multi-character literal. The compiler combines the ASCII values of those characters into a single integer value. This is why you see an integer output instead of the expected string.

For example, in this case the resulted integer "1953066599" is obtained by:

't' == 0x74; 'e' == 0x65; 's' == 0x73; 't' == 0x74; 'i' == 0x69; 'n' == 0x6e; 'g' == 0x67;

0x74657374696e67 is 1953066599.