# Literals

— defined for integers, reals, strings, and symbols.

## Integers

An integer is any group of
digits defining a number between -2e+31 and 2e+31 - 1. It
cannot contain a decimal point or an exponent. Integers have
several different literal notations, but regardless of
notation, all integers are 32 bit signed numbers. They are
flagged internally with their respective notations and Gamma
attempts to maintain and return the notation when the integer
is printed.

**Table 4. Integers**

Notation | Description | Example |
---|

| Decimal notation | 539 |

0b | Binary notation | 0b1011 |

0o | Octal notation | 0o462 |

0x | Hexadecimal notation | 0x35fc |

' ' | Contents are a character. | 'M' |

## Real numbers

A real number is any group
of digits defining a number less than -2e+31,
greater than 2e+31 - 1, or containing a
non-zero mantissa. It can contain a decimal
point, and it may end with the letter e
followed by a signed exponent.

**Table 5. Real numbers**

Notation | Description | Example |
---|

[0-9].[0-9]e[+|-][0-9] | Double-precision 64 bit floating-point
number. | 2.56e-7 |

## Strings

A string may
have any number of characters. The special forms \n, \t, \f
and \r denote newline, tab, form feed, and carriage return
respectively. The double quote (") and backslash (\)
characters may be embedded in a string by preceding them with
a backslash.

**Table 6. Strings**

Notation | Description | Example |
---|

" " | Contents are a string. | "Good morning." |

## Symbols

Generally, symbol names
are made up of alpha-numeric characters and underscores.

**Table 7. Symbols**

Notation | Description | Example |
---|

[a-z,A-Z,0-9] | One or
more characters chosen from : a-z, A-Z, 0-9
are valid for symbol names. | Epax15 |

_ | A _ (underscore) is allowed in any
part of a symbol name. This symbol is generally used to
separate words in a symbol name. The use of this
character at the beginning and end of a symbol is reserved
for system use. | `my_var_name` |

\ | Any non-alphanumeric
character other than ` _ ` must
be preceded by a backslash to be used in a
symbol name. | Ft\+\$sq |

## Other Data Types

The literal
representation for all other Gamma data types is discussed
in the reference entry associated with creating or accessing
that data type, as given in the table below.

**Table 8. Other Data Types**