I'm new to Go, and there is a question.
As I know, the following two snippets are basically the same.
i := 0
var i = 0
but why can't var statement be used in for loop?
for var i = 0; i < 10; i++ {
//do something
}
There will be a syntax error: var declaration not allowed in for initializergo
Why is it designed this way? Are there any thoughts in it?
I would appreciate it if someone could tell me.
The initialisation statement in this form of the for clause can't be any kind of statement but must be a "simple statement" (one case of such statements is the "short variable declaration" you saw working).
As for the reason, it's just like many other choices in the Go language: to keep your code readable and looking like the Go code of other developpers: if you could put any kind of statement here, the for loop wouldn't always be easily identifiable (and would mix concerns other than loop initialization).