How does the following program which assigns a variable name to an untyped constant n work? package mainįmt.Printf("type %T value %v", name, name) In the above line of code, the constant hello doesn't have a type. What type does a string constant belong to? The answer is they are untyped.Ī string constant like "Hello World" does not have any type. For example, strings like "Hello World", "Sam" are all constants in Go. String Constants, Typed and Untyped ConstantsĪny value enclosed between double quotes is a string constant in Go. prog.go:9:8: const initializer math.Sqrt(4) is not a constant The function math.Sqrt(4) will be evaluated only during run time and hence const b = math.Sqrt(4) fails to compile with error.
In the above program, a is a variable and hence it can be assigned to the result of the function math.Sqrt(4) (We will discuss functions in more detail in a separate tutorial).ī is a constant and the value of b needs to be known at compile time. Hence it cannot be assigned to a value returned by a function call since the function call takes place at run time. The value of a constant should be known at compile time. This program will fail to run with compilation error cannot assign to a. This is not allowed since a is a constant. In the program below, we are trying to assign another value 89 to a. The above program prints, JohnĬonstants, as the name indicate, cannot be reassigned again to any other value. In the above program, we have declared 3 constants name, age and country. An example to define a group of constants using this syntax is provided below. There is also another syntax to define a group of constants using a single statement.
In the above code a is a constant and it is assigned the value 50.
GOLAND FMT ON SAVE HOW TO
Let's see how to declare a constant using an example. The keyword const is used to declare a constant. The term constant in Go is used to denote fixed values such as 95
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