package main

import "fmt"

func main() {
    // 1. Declaration
    // Booleans can only be true or false.
    // The zero value is false.
    var isActive bool   // false by default
    isValid := true     // inferred as bool

    fmt.Println("isActive:", isActive)
    fmt.Println("isValid:", isValid)

    // 2. Logical Operators
    // && (AND), || (OR), ! (NOT)
    a := true
    b := false

    fmt.Println("a && b:", a && b) // false
    fmt.Println("a || b:", a || b) // true
    fmt.Println("!a:", !a)         // false

    // 3. Short-Circuit Evaluation
    // Go evaluates the left side first. If the result is already determined,
    // the right side is NOT executed.
    
    // In (true || check()), check() is NEVER called.
    if true || expensiveCheck() {
        fmt.Println("Short-circuit OR: skipped expensive check")
    }

    // In (false && check()), check() is NEVER called.
    if false && expensiveCheck() {
        // Unreachable
    } else {
        fmt.Println("Short-circuit AND: skipped expensive check")
    }
}

func expensiveCheck() bool {
    fmt.Println("Running expensive check...")
    return true
}