ios8:swift(1)

fundamental types:

Int Double Float Bool String

collection types:

Array Dictionary

declare constants with "let"

declare variables with "var"

with annotation(rarely used

eg:

    let a:String="good";
    var msg:String="hello";
    var a,b,c:Double;

to show a constant or variable with println (followed by a line break) or print

comments: //(single line) or /* */ (multiline)

Integers: signed and unsigned integer

8,16,32,64bit, prefer Int

in 32-bit system, Int and Int32 have same size

in 64-bit system, Int and Int64 have same size

Floating-point number:

Double: 64bit(15 decimal digits)

Float: 32bit(6 decimal digits)