Golang中的运行时常量

Question

In some languages, such as Java and C++, constants can be created and then assigned their value during the constructor (and then not changed after that). Is there any way to do this in Golang so that a constant whose value won't be known until runtime can be created? Thanks in advance!

Answer 1

Constants in go are set at compile time, see the relevant section in the docs here: https://golang.org/doc/effective_go.html#constants

Constants in Go are just that—constant. They are created at compile time, even when defined as locals in functions, and can only be numbers, characters (runes), strings or booleans. Because of the compile-time restriction, the expressions that define them must be constant expressions, evaluatable by the compiler. For instance, 1<<3 is a constant expression, while math.Sin(math.Pi/4) is not because the function call to math.Sin needs to happen at run time.