GoLang Tutorial - Structs and receiver methods
A struct is just a collect of fields.
In the following code, we define a struct called "Person", and then initialize it in two ways.
Note that we can not only access a specific field of a struct but also we can modify the value of any field.
Go does not have classes. However, we can define methods on types.
A method is a function with a special receiver argument.
The following example shows how we use (or create) the method of the struct.
In the code, we defined a method called (p Person) hello():
func (p Person) hello() {}
It is a receiver in Go terms and the syntax looks like this:
It's a Go way of creating a method for a struct!
As commented in the code below, it's a value type. We'll soon see a pointer type receiver like this:
func (p *Person) hasBirthday() {}
Here is our full code:
The next example shows how we modified the data of the struct. In the code, we defined a method (receiver) called (p *Person) hasBirthday(). Note that it's taking a pointer:
Another example of a receiver:
The code: stringer.go
We made a method called String() which enables us to customize print for the Animal struct.
Similar to the previous example. This time, we customize the IP-addresses:
The code: ip_addr.go
We made a method called String() which enables us to customize print for the [4]byte array. For instance, IPAddr{1, 2, 3, 4} will be print as "1.2.3.4".
The following is an example code showing one of the ways of constructing a struct.
First, it creates an empty slice of struct pointers, create a struct struct pointer, filled in the elements of the struct, then finally attach the struct pointer to the list of pointers:
The code: city-struct.go
Go Tutorial
- GoLang Tutorial - HelloWorld
- Calling code in an external package & go.mod / go.sum files
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- Structs and receiver methods
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- Web Application Part 0 (Introduction)
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