abstract struct Int
inherits Number
¶
Int is the base type of all integer types.
There are four signed integer types: Int8, Int16, Int32 and Int64,
being able to represent numbers of 8, 16, 32 and 64 bits respectively.
There are four unsigned integer types: UInt8, UInt16, UInt32 and UInt64.
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 the lowest between Int32, Int64 and UInt64
in which the number fits:
1 # Int32
1_i8 # Int8
1_i16 # Int16
1_i32 # Int32
1_i64 # Int64
1_u8 # UInt8
1_u16 # UInt16
1_u32 # UInt32
1_u64 # UInt64
+10 # Int32
-20 # Int32
2147483648 # Int64
9223372036854775808 # UInt64
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 0o:
0o123 # == 83
Hexadecimal numbers start with 0x:
0xFE012D # == 16646445
0xfe012d # == 16646445
Included modules
Comparable
Comparable
Comparable
Direct known subclasses
BigInt
Int128
Int16
Int32
Int64
Int8
UInt128
UInt16
UInt32
UInt64
UInt8
Class methods¶
.from_io(io : IO, format : IO::ByteFormat) : self
¶
(io : IO, format : IO::ByteFormat) : self
Reads an integer from the given io in the given format.
See also: IO#read_bytes.
Methods¶
#%(other : Int)
¶
View source
(other : Int)
#&**(exponent : Int) : self
¶
(exponent : Int) : self
Returns the value of raising self to the power of exponent.
Raises ArgumentError if exponent is negative: if this is needed,
either use a float base or a float exponent.
Intermediate multiplication will wrap around silently in case of overflow.
2 &** 3 # => 8
2 &** 0 # => 1
2 &** -1 # ArgumentError
#**(exponent : Float) : Float64
¶
(exponent : Float) : Float64
Returns the value of raising self to the power of exponent.
2 ** 3.0 # => 8.0
2 ** 0.0 # => 1.0
2 ** -1.0 # => 0.5
#**(exponent : Int) : self
¶
(exponent : Int) : self
Returns the value of raising self to the power of exponent.
Raises ArgumentError if exponent is negative: if this is needed,
either use a float base or a float exponent.
Raises OverflowError in case of overflow.
2 ** 3 # => 8
2 ** 0 # => 1
2 ** -1 # ArgumentError
#//(other : Int::Primitive)
¶
(other : Int::Primitive)
Divides self by other using floored division.
In floored division, given two integers x and y: * q = x / y is rounded toward negative infinity * r = x % y has the sign of the second argument * x == q*y + r
For example:
x y x / y x % y
5 3 1 2
-5 3 -2 1
5 -3 -2 -1
-5 -3 1 -2
Raises if other is zero, or if other is -1 and
self is signed and is the minimum value for that
integer type.
#<<(count : Int)
¶
(count : Int)
Returns the result of shifting this number's bits count positions to the left.
- If count is greater than the number of bits of this integer, returns 0
- If count is negative, a right shift is performed
8000 << 1 # => 16000
8000 << 2 # => 32000
8000 << 32 # => 0
8000 << -1 # => 4000
#<=>(other : BigDecimal)
¶
(other : BigDecimal)
The comparison operator. Returns 0 if the two objects are equal,
a negative number if this object is considered less than other,
a positive number if this object is considered greater than other,
or nil if the two objects are not comparable.
Subclasses define this method to provide class-specific ordering.
The comparison operator is usually used to sort values:
# Sort in a descending way:
[3, 1, 2].sort { |x, y| y <=> x } # => [3, 2, 1]
# Sort in an ascending way:
[3, 1, 2].sort { |x, y| x <=> y } # => [1, 2, 3]
#>>(count : Int)
¶
(count : Int)
Returns the result of shifting this number's bits count positions to the right. Also known as arithmetic right shift.
- If count is greater than the number of bits of this integer, returns 0
- If count is negative, a left shift is performed
8000 >> 1 # => 4000
8000 >> 2 # => 2000
8000 >> 32 # => 0
8000 >> -1 # => 16000
-8000 >> 1 # => -4000
#bit(bit)
¶
(bit)
Returns this number's bitth bit, starting with the least-significant.
11.bit(0) # => 1
11.bit(1) # => 1
11.bit(2) # => 0
11.bit(3) # => 1
11.bit(4) # => 0
#bit_length : Int32
¶
: Int32
Returns the number of bits of this int value.
“The number of bits” means that the bit position of the highest bit which is different to the sign bit. (The bit position of the bit 2**n is n+1.) If there is no such bit (zero or minus one), zero is returned.
I.e. This method returns ceil(log2(self < 0 ? -self : self + 1)).
0.bit_length # => 0
1.bit_length # => 1
2.bit_length # => 2
3.bit_length # => 2
4.bit_length # => 3
5.bit_length # => 3
# The above is the same as
0b0.bit_length # => 0
0b1.bit_length # => 1
0b10.bit_length # => 2
0b11.bit_length # => 2
0b100.bit_length # => 3
0b101.bit_length # => 3
#bits(range : Range)
¶
(range : Range)
Returns the requested range of bits
0b10011.bits(0..1) # => 0b11
0b10011.bits(0..2) # => 0b11
0b10011.bits(0..3) # => 0b11
0b10011.bits(0..4) # => 0b10011
0b10011.bits(0..5) # => 0b10011
0b10011.bits(1..4) # => 0b1001
#bits_set?(mask)
¶
(mask)
Returns true if all bits in mask are set on self.
0b0110.bits_set?(0b0110) # => true
0b1101.bits_set?(0b0111) # => false
0b1101.bits_set?(0b1100) # => true
#chr
¶
Returns a Char that has the unicode codepoint of self.
Raises ArgumentError if this integer's value doesn't fit a char's range (0..0x10ffff).
97.chr # => 'a'
#digits(base = 10) : Array(Int32)
¶
(base = 10) : Array(Int32)
Returns the digits of a number in a given base. The digits are returned as an array with the least significant digit as the first array element.
12345.digits # => [5, 4, 3, 2, 1]
12345.digits(7) # => [4, 6, 6, 0, 5]
12345.digits(100) # => [45, 23, 1]
-12345.digits(7) # => ArgumentError
#gcd(other : self) : self
¶
(other : self) : self
Returns the greatest common divisor of self and other. Signed
integers may raise OverflowError if either has value equal to MIN of
its type.
5.gcd(10) # => 5
5.gcd(7) # => 1
#humanize_bytes(precision : Int = 3, separator = '.', *, significant : Bool = true, format : BinaryPrefixFormat = :IEC) : String
¶
(precision : Int = 3, separator = '.', *, significant : Bool = true, format : BinaryPrefixFormat = :IEC) : String
Prints this integer as a binary value in a human-readable format using
a BinaryPrefixFormat.
Values with binary measurements such as computer storage (e.g. RAM size) are
typically expressed using unit prefixes based on 1024 (instead of multiples
of 1000 as per SI standard). This method by default uses the IEC standard
prefixes (Ki, Mi, Gi, Ti, Pi, Ei, Zi, Yi) based on powers of
1000 (see BinaryPrefixFormat::IEC).
format can be set to use the extended range of JEDEC units (K, M, G,
T, P, E, Z, Y) which equals to the prefixes of the SI system
except for uppercase K and is based on powers of 1024 (see
BinaryPrefixFormat::JEDEC).
1.humanize_bytes # => "1B"
1024.humanize_bytes # => "1.0kiB"
1536.humanize_bytes # => "1.5kiB"
524288.humanize_bytes # => "512kiB"
1073741824.humanize_bytes(format: :IEC) # => "1.0GiB"
See Number#humanize for more details on the behaviour and arguments.
#humanize_bytes(io : IO, precision : Int = 3, separator = '.', *, significant : Bool = true, format : BinaryPrefixFormat = :IEC) : Nil
¶
(io : IO, precision : Int = 3, separator = '.', *, significant : Bool = true, format : BinaryPrefixFormat = :IEC) : Nil
Prints this integer as a binary value in a human-readable format using
a BinaryPrefixFormat.
Values with binary measurements such as computer storage (e.g. RAM size) are
typically expressed using unit prefixes based on 1024 (instead of multiples
of 1000 as per SI standard). This method by default uses the IEC standard
prefixes (Ki, Mi, Gi, Ti, Pi, Ei, Zi, Yi) based on powers of
1000 (see BinaryPrefixFormat::IEC).
format can be set to use the extended range of JEDEC units (K, M, G,
T, P, E, Z, Y) which equals to the prefixes of the SI system
except for uppercase K and is based on powers of 1024 (see
BinaryPrefixFormat::JEDEC).
1.humanize_bytes # => "1B"
1024.humanize_bytes # => "1.0kiB"
1536.humanize_bytes # => "1.5kiB"
524288.humanize_bytes # => "512kiB"
1073741824.humanize_bytes(format: :IEC) # => "1.0GiB"
See Number#humanize for more details on the behaviour and arguments.
#lcm(other : Int)
¶
(other : Int)
Returns the least common multiple of self and other.
Raises OverflowError in case of overflow.
abstract
#popcount
¶
Counts 1-bits in the binary representation of this integer.
5.popcount # => 2
-15.popcount # => 29
#remainder(other : Int)
¶
View source
(other : Int)
#round(mode : RoundingMode) : self
¶
(mode : RoundingMode) : self
Rounds self to an integer value using rounding mode.
The rounding mode controls the direction of the rounding. The default is
RoundingMode::TIES_EVEN which rounds to the nearest integer, with ties
(fractional value of 0.5) being rounded to the even neighbor (Banker's rounding).
#tdiv(other : Int)
¶
(other : Int)
Divides self by other using truncated division.
In truncated division, given two integers x and y:
* q = x.tdiv(y) is rounded toward zero
* r = x.remainder(y) has the sign of the first argument
* x == q*y + r
For example:
x y x / y x % y
5 3 1 2
-5 3 -1 -2
5 -3 -1 2
-5 -3 1 -2
Raises if other is 0, or if other is -1 and
self is signed and is the minimum value for that
integer type.
#to_big_i : BigInt
¶
: BigInt
Returns a BigInt representing this integer.
require "big"
123.to_big_i
#to_io(io : IO, format : IO::ByteFormat)
¶
(io : IO, format : IO::ByteFormat)
Writes this integer to the given io in the given format.
See also: IO#write_bytes.