Type detection: Difference between revisions

</pre>

=={{header|Crystal}}==

<lang Ruby>def print_type(x)

puts "Compile-time type of #{x} is #{typeof(x)}"

puts " Actual runtime type is #{x.class}" if x.class != typeof(x)

end

print_type 123

print_type 123.45

print_type rand < 0.5 ? "1" : 0

print_type rand < 1.5

print_type nil

print_type 'c'

print_type "str"

print_type [1,2]

print_type({ 2, "two" })

print_type({a: 1, b: 2})

print_type ->(x : Int32){ x+2 > 0 }

</lang>

{{out}}

<pre>Compile-time type of 123 is Int32

Compile-time type of 123.45 is Float64

Compile-time type of 0 is (Int32 | String)

Actual runtime type is Int32

Compile-time type of true is Bool

Compile-time type of is Nil

Compile-time type of c is Char

Compile-time type of str is String

Compile-time type of [1, 2] is Array(Int32)

Compile-time type of {2, "two"} is Tuple(Int32, String)

Compile-time type of {a: 1, b: 2} is NamedTuple(a: Int32, b: Int32)

Compile-time type of #<Proc(Int32, Bool):0x5645695ab9f0> is Proc(Int32, Bool)