Switch in Go

Introduction

The switch is a powerful tool in Go, allowing programmers to make decisions based on multiple cases. Unlike conditionals with if and else, switch is often more readable, especially when dealing with many conditions.

• Switch Fundamentals
  • Basic Switch
  • Switch with Multiple Conditions in a Case
  • Switch with Initialiser
  • Type Switch

Switch Fundamentals

1. Equality Check: The switch compares the given expression against the values of each case.
2. Single Execution: Unlike other languages, in Go, once a case matches, the program exits the switch block. No explicit "break" is needed.
3. Default Clause: If no case matches, the code under default will be executed. However, default is optional.

Basic Switch

day := "thursday"

switch day {
case "monday":
	fmt.Println("Today is Monday.")
case "tuesday":
	fmt.Println("Today is Tuesday.")
default:
	fmt.Println("It is neither Monday nor Tuesday.")
}

Switch with Multiple Conditions in a Case

You can combine multiple possible values in a single case:

letter := 'B'

switch letter {
case 'A', 'E', 'I', 'O', 'U':
	fmt.Println("Vowel")
default:
	fmt.Println("Consonant")
}

Switch with Initialiser

Just like the if statement, switch can also have an initialisation:

switch num := 5; num {
case 1, 3, 5, 7, 9:
	fmt.Println("Odd number")
default:
	fmt.Println("Even number")
}

Type Switch

Go also supports a type-based switch, which is useful when working with interfaces:

var x interface{} = "text"

switch x.(type) {
case int:
	fmt.Println("x is an integer")
case string:
	fmt.Println("x is a string")
default:
	fmt.Println("Unknown type")
}

Conclusion

The switch statement in Go offers a clean and efficient way to handle multiple conditions. Whether checking values or types, switch makes code more organised and readable.

Happy coding!