What is the correct syntax for accessing a structure variable?

Question

What is the correct syntax for accessing a member variable? I am currently trying to do the following:

struct one { var name:String = "Ric" var address:String = "Lee" } one.name 

But the last line throws an error:

'one.Type' has no member named 'name'

How can I access a variable in my structure?

Answer 1

It looks like you defined the structure, but did not create an instance of it. If you create an instance, you can access its name and address properties.

 struct one { var name: String = "Ric" var address: String = "Lee" } var x = one() x.name 

This can be confusing because you can set default values ​​in the definition, which can make it look like you are creating something.

Answer 2

When you declare a structure in order to use it, you need to create an instance. The one structure is a type, just as Int is a type, and to use it you need to create an Int type variable:

 var myInt:Int = 10 

Similarly, once you define a structure, you can instantiate this structure and assign a variable:

 var myStruct = one() 

at this point you can access the properties and methods of the instance:

 println(myStruct.name) 

If you don't need an instance instead, you must declare the properties and methods as static :

 struct one { static var name: String = "Ric" static var address: String = "Lee" } 

and that the only case where you can refer to properties and call methods using a type, not an instance of a type:

 println(one.name) 

Side note: by convention, classes and struct (and, more commonly, any type) should be named with the first character in uppercase.