How do I print the type or class of a variable in Swift?

Answer

You can use the _stdlib_getDemangledTypeName(). Paste this into an empty playground:

import Foundation

class PureSwiftClass {
}

var myvar0 = NSString() // Objective-C class
var myvar1 = PureSwiftClass()
var myvar2 = 42
var myvar3 = "Hans"

println( "TypeName0 = \(_stdlib_getDemangledTypeName(myvar0))")
println( "TypeName1 = \(_stdlib_getDemangledTypeName(myvar1))")
println( "TypeName2 = \(_stdlib_getDemangledTypeName(myvar2))")
println( "TypeName3 = \(_stdlib_getDemangledTypeName(myvar3))")
and get this as output:

TypeName0 = NSString
TypeName1 = __lldb_expr_26.PureSwiftClass
TypeName2 = Swift.Int
TypeName3 = Swift.String
Original answer:

Prior to Xcode 6.3 _stdlib_getTypeName got the mangled type name of a variable. Ewan Swick's blog entry helps to decipher these strings:

e.g. _TtSi stands for Swift's internal Int type.