[Author: @mdimamhosen Date: 2025-04-19 Category: interview-qa/logical_operators Tags: [go, logical_operators] ]

Logical Operators

Logical operators are used to determine the logic between variables or values.

1. Logical and (&&)

Returns true if both statements are true

2. Logical or (||)

Returns true if one statements is true

3. Logical not (!)

Reverse the result, returns false if the result is true

package main

import "fmt"

func main() {
	fmt.Println(true && true) // true
	fmt.Println(true && false) // false

	fmt.Println(true || true) // true
	fmt.Println(false || false) // false

	fmt.Println(!true) // false
	fmt.Println(!false) // true
}

Frequently Asked Questions

1. What is the difference between && and || in Go?

Answer:

• && (Logical AND) returns true only if both conditions are true.
• || (Logical OR) returns true if at least one condition is true.

Code Example:

package main

import "fmt"

func main() {
	fmt.Println(true && false) // false
	fmt.Println(true || false) // true
}

2. How does the ! operator work in Go?

Answer:

• The ! (Logical NOT) operator reverses the boolean value.

Code Example:

package main

import "fmt"

func main() {
	fmt.Println(!true)  // false
	fmt.Println(!false) // true
}

3. Can logical operators be used with non-boolean values?

Answer:

• No, logical operators in Go work only with boolean values.

4. How can I combine multiple logical operators in a single expression?

Answer:

• You can combine them using parentheses to control precedence.

Code Example:

package main

import "fmt"

func main() {
	fmt.Println((true && false) || true) // true
}

5. What is the precedence of logical operators in Go?

Answer:

• ! has the highest precedence, followed by &&, and then ||.

Code Example:

package main

import "fmt"

func main() {
	fmt.Println(!true || false && true) // false
}

6. How can I use logical operators in conditional statements?

Answer:

• Logical operators are often used in if statements to combine conditions.

Code Example:

package main

import "fmt"

func main() {
	if true && !false {
		fmt.Println("Condition met")
	}
}

7. Can logical operators short-circuit in Go?

Answer:

• Yes, && and || short-circuit. For example, && stops evaluating if the first condition is false.

Code Example:

package main

import "fmt"

func main() {
	fmt.Println(false && (5 > 3)) // false (5 > 3 is not evaluated)
}

8. How can I debug logical expressions in Go?

Answer:

• Use fmt.Println to print intermediate results.

Code Example:

package main

import "fmt"

func main() {
	condition1 := true
	condition2 := false
	fmt.Println(condition1 && condition2) // false
}

9. Can logical operators be used in loops?

Answer:

• Yes, they can be used in loop conditions.

Code Example:

package main

import "fmt"

func main() {
	for i := 0; i < 10 && i%2 == 0; i++ {
		fmt.Println(i)
	}
}

10. What happens if I use logical operators with nil values?

Answer:

• Logical operators cannot be directly used with nil. You need to compare nil explicitly.

Code Example:

package main

import "fmt"

func main() {
	var ptr *int = nil
	fmt.Println(ptr == nil || true) // true
}