Strange Go Language Iota

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Go language iota A bit strange, look at the following code:

Package MainImport ( "FMT")Const ( testmin =1TestAtestb = Iota testc)                func Main(){FMT. Printf("testmin:%d\n", testmin)        FMT. Printf("testa:%d\n", TestA)        FMT. Printf("testb:%d\n", testb)        FMT. Printf("testc:%d\n", testc)}

What is the execution result of the above code?

As a result, when you see the results, the usage of iota is basically mastered:

/*TestMin:-1TestA:-1TestB:2TestC:3*/

Let's look at one more example:

Package MainImport ( "FMT")Const (i=1<<iota j=3<<iota k l)func Main(){FMT. Println("i=", i)  FMT. Println("j=", J)  FMT. Println("k=", K)  FMT. Println("l=", L)}

Execution Result:

i= 1j= 6k= 12l= 24

K equals 12,l equals 24 How is it got out?

    i=1<<iota    j=3<<iota    k    l

That is

    i=1<<0    j=3<<1    k=3<<2    l=3<<3

Iota each occurrence, automatically add 1, and the preceding operand if not specified, the default is to use the previous one, here is 3;