Constants

Constants are declared like variables but use the const keyword. Constants can't use the := short declaration syntax.

Constants can be character, string, boolean, or numeric values. They can not be more complex types like slices, maps and structs, which are types we will explain later.

As the name implies, the value of a constant can't be changed after it has been declared.

Use two separate constants

Something weird is happening in this code.

What should be happening is that we create 2 separate constants: premiumPlanName and basicPlanName. Right now it looks like we're trying to overwrite one of them.