Go Booleans (Relational and Logical Operators)

Go Boolean Data Types

A boolean data type represents logical entities. It can have two possible values: true or false.

We use the bool keyword to create boolean-type variables. For example,

package main
import "fmt"

func main() {

  var boolTrue bool = true
  var boolFalse bool = false

  fmt.Println("The boolean values are", boolTrue, "and", boolFalse)
}

Output:

The boolean values are true and false

Relational Operators in Golang

We use the relational operators to compare two values or variables. For example,

number1 := 9
number2 := 3

result := number1 > number2

Here, > is a relational (comparison) operator. It compares whether number1 is greater than number2.

Relational Operators use boolean values (true and false) to return the validity of a relation. It returns:

• true if the comparison between operators is correct.
• false if the comparison between operators is incorrect.

Different Types of Relational Operators in Golang

Here's a list of various relational operators available in Go:

Example: Relational Operator in Go

// Program to illustrate the working of Relational Operators

package main
import "fmt"

func main() {

  number1 := 12
  number2 := 20
  var result bool

  // equal to operator
  result = (number1 == number2)

  fmt.Printf("%d == %d returns %t \n", number1, number2, result)

  // not equal to operator
  result = (number1 != number2)

  fmt.Printf("%d != %d returns %t \n", number1, number2, result)

  // greater than operator
  result = (number1 > number2)

  fmt.Printf("%d > %d returns %t \n", number1, number2, result)

  // less than operator
  result = (number1 < number2)

  fmt.Printf("%d < %d returns %t \n", number1, number2, result)

}

Output

12 == 20 returns false 
12 != 20 returns true 
12 > 20 returns false 
12 < 20 returns true 

Logical Operators in Go

Logical operators return either true or false depending upon the conditions.

Example: Logical Operator in Go

// Program to illustrate the working of Logical Operator

package main
import "fmt"

func main() {

  number1 := 6
  number2 := 12
  number3 := 6
  var result bool

  // returns false because number1 > number2 is false
  result = (number1 > number2) && (number1 == number3)

  fmt.Printf("Result of AND operator is %t \n", result)

  // returns true because number1 == number3 is true
  result = (number1 > number2) || (number1 == number3)

  fmt.Printf("Result of OR operator is %t \n", result)
  
  // returns false because number1 == number3 is true
  result = !(number1 == number3);

  fmt.Printf("Result of NOT operator is %t \n", result)

}

Output

Result of AND operator is false 
Result of OR operator is true 
Result of NOT operator is false 

Go Boolean Expression

In programming, expressions that return boolean values: true or false are known as boolean expressions. For example,

number1 := 5
number2 := 8

result := number1 > number2

Here, number1 > number2 is a boolean expression that returns false.

Why boolean expression?

Boolean expressions are used to create decision-making programs. Suppose we want to create a program that determines whether a person can vote or not.

We can use a boolean expression to check if the age of that person is greater than 18. If true, the person can vote. If false, cannot vote.

We will learn more about these decision-making programs in Go if...else.