一文搞懂Golang中iota的用法和原理

//const关键字出现时将被重置为0
const (
    a = iota  //0
    b         //1
)
//不同const定义块互不干扰
const (
    c = iota //0
)

const (
    n1 = iota //0
    n2 		  //1
    n3 		  //2
    n4 		  //3
)

const (
    a = iota  //0
    
    b		  //1
    
    //此行是注释
    c         //2
)

const (
    a = iota //0
    _
    b        //2
)

const (
    a = iota     // a=0
    b = iota     // b=1
    c = iota     // c=2
  )

const (
    a, b = iota, iota // a=0,b=0
    c, d              // c=1,d=1
)

const (
    a = 100 //  a=100
    b = iota // b=1
    c = iota // c=2
    d        // d=3
)

const (
    a = iota // a=0
    b = 100  // b=100
    c = iota // c=2
    d        // d=3
)

const (
   a = iota       //  iota = 0 
   b = 1 + iota  // iota = 1
   c           // iota = 2
)

const iota = 0 // Untyped int.iota

ValueSpec struct {
 Doc *CommentGroup // associated documentation; or nil
 Names []*Ident // value names (len(Names) > 0)
 Type Expr // value type; or nil
 Values []Expr // initial values; or nil
 Comment *CommentGroup // line comments; or nil
}

for iota, spec := range ValueSpecs {
 for i, name := range spec.Names {
 obj := NewConst(name, iota...) //此处将iota传入，用于构造常量
 ...
 }
}