I've learned about maps and slices in GO. However, they can only hold items of uniform types. Today, I dive into learning about structs which can hold a combination of different types.

Structs

Structs are a common data structure in many programming languages and are useful for managing real-world records and related information of different types. The syntax is also similar to that of other languages.

var name struct {
variable type
variable type
variable type
…
}

You can have any number of variables in a struct. Like other things in GO, the default values are the appropriate zero values for the data types. Here is an example:

Assigning Values to a Struct

In order to set values you use the dot operator.





This is similar to how other programming languages do it, as well.

Type Definition

If I need more than one record based on aStruct, I can either repeat the definition of the struct, or I can create a new type based on it. I can then declare variables based on the type. So, declare once, use often. Here is the syntax for a defined type based on a struct.





This looks like the same code. There is one major difference: the type keyword replaces the var keyword. Once defined this way, I can declare variables based on the type:

Structs and Functions

Being a type, I can pass a struct into a function as an argument.






One thing I need to remember is that GO passes parameters by value, so modifying a struct within a function takes extra work. It's better to treat GO functions as pure functions and return a modified copy.

There is an issue. If my structs are large, there may be memory pressure as a result of creating copies in functions. That's where passing a pointer to to a struct can help.

I'll tackle that next time.

Tags: GO, struct, assignment, declaring, type definition, functions

I'm done with GO packages for now. I want to get back to the core language. Today I learn about arrays. Read More…

Tags: GO, arrays, declaring, assignment, loops, Iterator, blank identifier