In Go, constants are declared like variables, but with the const
keyword. Constants can be character, string, boolean, or numeric values. Constants cannot be declared using the :=
syntax.
const Pi = 3.14
Variables in Go are explicitly declared and used by the compiler to e.g. check type-correctness of function calls.
var x int = 1
y := 2 // Short variable declarations, infer the type based on the assigned value
Go's basic types are:
bool
string
int int8 int16 int32 int64
uint uint8 uint16 uint32 uint64 uintptr
byte // alias for uint8
rune // alias for int32, represents a Unicode code point
float32 float64
complex64 complex128
The int
, uint
, and uintptr
types are usually 32 bits wide on 32-bit systems and 64 bits wide on 64-bit systems.
Variables declared without an explicit initial value are given their zero value. The zero value is:
0
for numeric types,false
for the boolean type, and""
(the empty string) for strings.