4.10 Characters

The type char represents single characters. The form of a character declaration is:

charvariable;   //comment

Characters are enclosed in single quotation marks ('). 'A', 'a' and '!' are character constants. The backslash character (\) is called the escape character . It is used to signal that a special character follows. For example, the character \t can be used to represent the single character "tab." \n is the newline character. It causes the output device to go to the beginning of the next line, similar to a return key on a typewriter. The character \\ is the backslash itself. Finally, characters can be specified by \nnn, where nnn is the octal code for the character. Table 4-3 summarizes these special characters. For a full list of ASCII character codes, see Appendix A.

Table 4-3. Special characters

Character	Name	Meaning
\b	Backspace	Move the cursor to the left one character.
\f	Form feed	Go to top of a new page.
\n	New line	Go to the next line.
\r	Return	Go to the beginning of the current line.
\t	Tab	Advance to the next tab stop (eight-column boundary).
\'	Apostrophe or single quotation mark	The character '.
\"	Double quote	The character ".
\\	Backslash	The character \.
\nnn	The character nnn	The character number nnn (octal).
\xNN	The character NN	The character number NN (hexadecimal).

While characters are enclosed in single quotes ('), a different data type, the string literal, is enclosed in double quotes ("). A good way to remember the difference between these two types of quotes is that single characters are enclosed in single quotes. Strings can have any number of characters (including double quote characters), and they are enclosed in double quotes.

Example 4-5 demonstrates the use of character variables by reversing three characters.

Example 4-5. print3/print3.cpp

#include <iostream>

char char1;     // first character 
char char2;     // second character
char char3;     // third character 

int main(  )
{
    char1 = 'A';
    char2 = 'B';
    char3 = 'C';
    std::cout << char1 << char2 << char3 << " reversed is " <<
            char3 << char2 << char1 << "\n";
    return (0);
}

When executed, this program prints:

ABC reversed is CBA