Elixir v1.4.5 Integer View Source
Functions for working with integers.
Link to this section Summary
Functions
Returns the ordered digits for the given integer
Performs a floored integer division
Determines if an integer is even
Determines if integer is odd
Computes the modulo remainder of an integer division
Parses a text representation of an integer
Returns a charlist which corresponds to the text representation of the given integer
Returns a charlist which corresponds to the text representation of integer in the given base
Returns a binary which corresponds to the text representation
of integer
Returns a binary which corresponds to the text representation
of integer in the given base
Returns the integer represented by the ordered digits
Link to this section Functions
digits(integer, pos_integer) :: [integer, ...]
Returns the ordered digits for the given integer.
An optional base value may be provided representing the radix for the returned
digits. This one must be an integer >= 2.
Examples
iex> Integer.digits(123)
[1, 2, 3]
iex> Integer.digits(170, 2)
[1, 0, 1, 0, 1, 0, 1, 0]
iex> Integer.digits(-170, 2)
[-1, 0, -1, 0, -1, 0, -1, 0]
floor_div(integer, neg_integer | pos_integer) :: integer
Performs a floored integer division.
Raises an ArithmeticError exception if one of the arguments is not an
integer, or when the divisor is 0.
Integer.floor_div/2 performs floored integer division. This means that
the result is always rounded towards negative infinity.
If you want to perform truncated integer division (rounding towards zero),
use Kernel.div/2 instead.
Examples
iex> Integer.floor_div(5, 2)
2
iex> Integer.floor_div(6, -4)
-2
iex> Integer.floor_div(-99, 2)
-50
Determines if an integer is even.
Returns true if the given integer is an even number,
otherwise it returns false.
Allowed in guard clauses.
Examples
iex> Integer.is_even(10)
true
iex> Integer.is_even(5)
false
iex> Integer.is_even(-10)
true
iex> Integer.is_even(0)
true
Determines if integer is odd.
Returns true if the given integer is an odd number,
otherwise it returns false.
Allowed in guard clauses.
Examples
iex> Integer.is_odd(5)
true
iex> Integer.is_odd(6)
false
iex> Integer.is_odd(-5)
true
iex> Integer.is_odd(0)
false
mod(integer, neg_integer | pos_integer) :: integer
Computes the modulo remainder of an integer division.
Integer.mod/2 uses floored division, which means that
the result will always have the sign of the divisor.
Raises an ArithmeticError exception if one of the arguments is not an
integer, or when the divisor is 0.
Examples
iex> Integer.mod(5, 2)
1
iex> Integer.mod(6, -4)
-2
parse(binary, 2..36) :: {integer, binary} | :error | no_return
Parses a text representation of an integer.
An optional base to the corresponding integer can be provided.
If base is not given, 10 will be used.
If successful, returns a tuple in the form of {integer, remainder_of_binary}.
Otherwise :error.
Raises an error if base is less than 2 or more than 36.
If you want to convert a string-formatted integer directly to a integer,
String.to_integer/1 or String.to_integer/2 can be used instead.
Examples
iex> Integer.parse("34")
{34, ""}
iex> Integer.parse("34.5")
{34, ".5"}
iex> Integer.parse("three")
:error
iex> Integer.parse("34", 10)
{34, ""}
iex> Integer.parse("f4", 16)
{244, ""}
iex> Integer.parse("Awww++", 36)
{509216, "++"}
iex> Integer.parse("fab", 10)
:error
iex> Integer.parse("a2", 38)
** (ArgumentError) invalid base 38
Returns a charlist which corresponds to the text representation of the given integer.
Inlined by the compiler.
Examples
iex> Integer.to_charlist(123)
'123'
iex> Integer.to_charlist(+456)
'456'
iex> Integer.to_charlist(-789)
'-789'
iex> Integer.to_charlist(0123)
'123'
to_charlist(integer, 2..36) :: charlist
Returns a charlist which corresponds to the text representation of integer in the given base.
base can be an integer between 2 and 36.
Inlined by the compiler.
Examples
iex> Integer.to_charlist(100, 16)
'64'
iex> Integer.to_charlist(-100, 16)
'-64'
iex> Integer.to_charlist(882681651, 36)
'ELIXIR'
Returns a binary which corresponds to the text representation
of integer.
Inlined by the compiler.
Examples
iex> Integer.to_string(123)
"123"
iex> Integer.to_string(+456)
"456"
iex> Integer.to_string(-789)
"-789"
iex> Integer.to_string(0123)
"123"
Returns a binary which corresponds to the text representation
of integer in the given base.
base can be an integer between 2 and 36.
Inlined by the compiler.
Examples
iex> Integer.to_string(100, 16)
"64"
iex> Integer.to_string(-100, 16)
"-64"
iex> Integer.to_string(882681651, 36)
"ELIXIR"
undigits([integer], integer) :: integer
Returns the integer represented by the ordered digits.
An optional base value may be provided representing the radix for the digits.
This one can be an integer >= 2.
Examples
iex> Integer.undigits([1, 2, 3])
123
iex> Integer.undigits([1, 4], 16)
20
iex> Integer.undigits([])
0