Go Language Struct (struct)

For example, an address has name, street, city, state, Pincode. As shown below, combine these three properties into a structureAddressIt makes sense.

Declare the structure:

　type Address struct {
　　　　　　name string　
　　　　　　street string
　　　　　　city string
　　　　　　state string
　　　　　　Pincode int
}

On the above,typeA keyword introduces a new type. It is followed by the name of the type (Address）and keywordstruct,To illustrate the structure we are defining. This structure contains a list of fields within the curly braces. Each field has a name and a type.

Note:We can also make them compact by combining fields of the same type, as shown in the following example:}}

type Address struct {
　　　　name, street, city, state string
　　　　Pincode int
}

Define structure:Syntax for declaring a structure:

var a Address

The above code creates aAddress typeVariables, by default, they are set to zero. For structures, zero means that all fields are set to their corresponding zero values. Therefore, the fields name, street, city, state are set to "", and Pincode is set to 0.

You can alsoInitialize a variable of a structure type using a structure literalAs shown below:

var a = Address{"Akshay", "PremNagar", "Dehradun", "Uttarakhand",　252636}

Note:

Always pass field values in the order they are declared in the structure. Similarly, you cannot initialize a subset of fields using the above syntax.

Go also supportsName: valueSyntax for initializing a structure (the order of fields is irrelevant when using this syntax). Moreover, this syntax only allows you to initialize a subset of fields. All uninitialized fields are set to their respective zero values.

For example:

var a = Address{"Akshay", "PremNagar", "Dehradun", "Uttarakhand",　252636}

package main　
　　
import \
　　
//Define structure type
type Address struct {　
　　　　Name string　
　　　　city string　
　　　　Pincode int
}　
　　
func main() {　
　　
　　　　　　　　//Declare a variable of type "struct"
　　　　　　　　//Initialize all struct fields
　　　　　　　　//Its value is zero
　　　　var a Address　　
　　　　fmt.Println(a)　
　　
　　　　　　　　//struct
　　　　　　　　//　Use structure literals to declare and initialize
　　　　a1　:= Address{"Akshay", "Dehradun",　3623572}　
　　
　　　　fmt.Println("Address"1: "a"1)　
　　
　　　　　　　　//When naming fields
　　　　　　　　//Initialize a structure
　　　　a2　:= Address{Name: "Anikaa", city: "Ballia", Pincode:　277001}　
　　
　　　　fmt.Println("Address"2: "a"2)　
　　
　　　　　　　　//Uninitialized fields are set to
　　　　　　　　//They correspond to zero values
　　　　a3　:= Address{Name: "Delhi"}　
　　　　fmt.Println("Address"3: "a"3)　
}

Output:

{ 0}
Address1: {Akshay Dehradun}　3623572}
Address2: {Anikaa Ballia}　277001}
Address3: {Delhi 0}

How to access the fields of the structure?

To accessOf the structureEach field, you must use a dot(.)Operator.

package main　
　　
import \
　　
//Define a structure　
type Car struct {　
　　　　Name, Model, Color string　
　　　　WeightInKg float64　
}　
　　
func main() {　
　　　　4", Color: \　1920}　
　　
　　　　　　　　//Access a struct field
　　　　　　　　//Using the dot operator
　　　　fmt.Println("Car Name: ", c.Name)　
　　　　fmt.Println("Car Color: ", c.Color)　
　　　　　　　　//Assign a new value
　　　　　　　　//Point to a struct field
　　　　c.Color = "Black"
　　　　　　
　　　　//Display the result
　　　　fmt.Println("Car: ", c)　
}

Output:

Car Name: {Ferrari
Car Color: {Red
Car: {Ferrari GTC4　Black　1920}

Pointer to a structure

In Golang, a pointer is a variable used to store the memory address of another variable. You can also create a pointer to a struct, as shown in the following example:

//　Pointer to a struct
package main　
　　
import \
　　
//　Define a structure
type Employee struct {　
　　　　firstName, lastName string　
　　　　age, salary int
}　
　　
func main() {　
　　
　　　　　　　　//Passing the address of a struct variable
　　　　　　　　//　emp8
　　　　emp8　:= &Employee{\"Sam\", \"Anderson\",　55,　6000}　
　　
　　　　　　　　//*　emp8,
　　　　　　　　//　emp8The firstName field of the structure
　　　　fmt.Println("First Name:", （*emp8).firstName)　
　　　　fmt.Println("Age:", （*emp8).age)　
}

Output:

First Name: Sam
Age:　55

Golang provides us with the option to use emp8.firstName instead of explicitly dereferencing（* emp8）.firstName to access the firstName field. The following example shows:

//Pointer to a structure
package main　
　　
import \
　　
//Define a structure
type Employee struct {　
　　　　firstName, lastName string　
　　　　age, salary int
}　
　　
func main() {　
　　
　　　　//Obtaining a pointer to a struct
　　　　emp8　:= &Employee{\"Sam\", \"Anderson\",　55,　6000}　
　　
　　　　　　　　//　emp8is used to access
　　　　　　　　//Field firstName
　　　　fmt.Println("First Name: ", emp8.firstName)　
　　　　fmt.Println("Age: ", emp8.age)　
}

Output:

First Name:
Age:　　55