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How to check if structure is empty in Golang?

Checking structure is empty or not: Here, we are going to learn how to check whether a structure is empty or not in Golang?
Submitted by Anshuman Singh, on July 03, 2019 [Last updated : March 05, 2023]

Golang Empty Structure

The size of an empty structure is zero in Golang. Here, empty structure means, there is no field in the structure.

Syntax

    Type structure_name struct {
    }

There are many ways to check if structure is empty. Examples are given below.

Golang code to check whether a structure in an empty or not

Example 1

package main

import (
  "fmt"
)

type Person struct {

}

func main() {
  var st Person
  if (Person{} == st) {
      fmt.Println("It is an empty structure")
  } else {
    fmt.Println("It is not an empty structure")
  }
}

It is an empty structure

Example 2

package main

import (
  "fmt"
)

type Person struct {
  age int
}

func main() {
  var st Person
  if (Person{20} == st) {
      fmt.Println("It is an empty structure")
  } else {
    fmt.Println("It is not an empty structure")
  }
}

It is not an empty structure

If a structure has fields, then how to check whether structure has been initialised or not?

Please follow given below examples...

Syntax

    Type structure_name struct {
        variable_name type
    }

Example 1

package main

import (
  "fmt"
  "reflect"
)

type Person struct {
  age int
}

func (x Person) IsStructureEmpty() bool {
  return reflect.DeepEqual(x, Person{})
}

func main() {
  x := Person{}

  if x.IsStructureEmpty() {
    fmt.Println("Structure is empty")
  } else {
    fmt.Println("Structure is not empty")
  }
}

Output

Structure is empty

Example 2

package main

import (
  "fmt"
  "reflect"
)

type Person struct {
  age int
}

func (x Person) IsStructureEmpty() bool {
  return reflect.DeepEqual(x, Person{})
}

func main() {
  x := Person{}
  x.age = 20
  if x.IsStructureEmpty() {
    fmt.Println("Structure is empty")
  } else {
    fmt.Println("Structure is not empty")
  }
}

Output

Structure is not empty

Using switch statement

Example 1

package main

import (
  "fmt"
)

type Person struct {
}

func main() {
  x := Person{}

  switch {
    case x == Person{}:
        fmt.Println("Structure is empty")
    default:
        fmt.Println("Structure is not empty")
  }
}

Output

Structure is empty

Example 2

package main

import (
  "fmt"
)

type Person struct {
  age int
}

func main() {
  x := Person{}

  switch {
    case x == Person{1}:
        fmt.Println("Structure is empty")
    default:
        fmt.Println("Structure is not empty")
  }
}

Output

Structure is not empty