If/Else & Switch

Conditional statements are used to make decisions in code.

Concept

The computer will check if a condition is true. If yes, run Code A. If no, run Code B (else).

When to use?

Validating user input (e.g., age > 17).

Business logic (e.g., if balance is enough, process transaction).

MAIN.GO

package main
import "fmt"
func main() {
    num := 7
    if num%2 == 0 {
        fmt.Println(num, "is Even")
    } else {
        fmt.Println(num, "is Odd")
    }
}

switch is a cleaner form of nested if-else chains.

When to use?

Use switch if you are comparing a single variable against many specific values. Examples: Checking days (Monday, Tuesday...), Checking order status (Pending, Paid, Shipped).

MAIN.GO

package main
import "fmt"
func main() {
    i := 2
    fmt.Print("Number ", i, " is ")
    switch i {
    case 1:
        fmt.Println("One")
    case 2:
        fmt.Println("Two")
    case 3:
        fmt.Println("Three")
    default:
        fmt.Println("Others")
    }
}