variable
First, the variable Notes
Variable names capitalized, other packages can be accessed call (public), the first letter lowercase variable names, and other packages can not access the call (private)
In the same field in a variable can be defined only once and can not be redefined
Second, ways to declare variables
1, after the first assignment statement
Keyword Variable name Variable type - >> var a int
Variable name = value - >> a = 10 - assignment requires the function body
2, and the assignment statement
Keyword = Value Variable Type Variable Name - >> var a int = 10
3, derivation type
Keyword variable name = value - >> var a = 10
4, a brief statement and assignment, only the function body
Variable name: = value - >> a: = 10
5, the anonymous variable: means for receiving unwanted return value of the function is generally used, a _
Third, the batch statement, the following
where (
a int
b int =10
c float
)
constant
First, constant declarations, must be assigned declaration
Keyword variable name = value - >> const a = 20
Second, the bulk assignment and precautions
If a plurality of constants constant back unassigned, assigned default values of the constants a, as
const (
a = 10
b =20
c // c is 20 at this time, taking the value of the variable thereon
)
Three, iota enumeration
Constant counter, can only be used in constant expressions, and with the use of const, plus 1 for each additional line cumulative, including blank lines, met const reset to 0, the assignment will encounter _ just do not show
const(
a = iota //a=0
b = 100 b =100
_ //iota=2
d //d=3
)
const(
a,b =iota+1,iota+2 //iota=0,a=1,b=2
c,d //iota=1,c=2,d=3
e,f //iota=2,e=3,f=4
)
Defined magnitude
const(
_ = iota
KB = 1 << (10 * iota) // 1 << 10 left 10
MB=1<<(10*iota) //1<<20
GB=1<<(10*iota) //1<<30
TB=1<<(10*iota) //1<<40
PB=1<<(10*iota) //1<<50
)