# Integers¶

There are five signed integer types, and five unsigned integer types:

Type Length Minimum Value Maximum Value
Int8 8 -128 127
Int16 16 −32,768 32,767
Int32 32 −2,147,483,648 2,147,483,647
Int64 64 −263 263 - 1
Int128 128 −2127 2127 - 1
UInt8 8 0 255
UInt16 16 0 65,535
UInt32 32 0 4,294,967,295
UInt64 64 0 264 - 1
UInt128 128 0 2128 - 1

An integer literal is an optional `+` or `-` sign, followed by a sequence of digits and underscores, optionally followed by a suffix. If no suffix is present, the literal's type is `Int32` if the value fits into `Int32`'s range, and `Int64` otherwise. Integers outside `Int64`'s range must always be suffixed:

``````1 # Int32

1_i8   # Int8
1_i16  # Int16
1_i32  # Int32
1_i64  # Int64
1_i128 # Int128

1_u8   # UInt8
1_u16  # UInt16
1_u32  # UInt32
1_u64  # UInt64
1_u128 # UInt128

+10 # Int32
-20 # Int32

2147483647  # Int32
2147483648  # Int64
-2147483648 # Int32
-2147483649 # Int64

9223372036854775807     # Int64
9223372036854775808_u64 # UInt64
``````

Suffix-less integer literals larger than `Int64`'s maximum value but representable within `UInt64`'s range are deprecated, e.g. `9223372036854775808`.

The underscore `_` before the suffix is optional.

Underscores can be used to make some numbers more readable:

``````1_000_000 # better than 1000000
``````

Binary numbers start with `0b`:

``````0b1101 # == 13
``````

Octal numbers start with a `0o`:

``````0o123 # == 83
``````

Hexadecimal numbers start with `0x`:

``````0xFE012D # == 16646445
0xfe012d # == 16646445
``````