Logical Operators

Logical operators operate on bool values and produce bool results.

Logical NOT

The logical NOT operator ! negates its operand.

fn main() -> i32 {
    let a = !false;   // true
    let b = !true;    // false
    let c = !!true;   // true (double negation)
    if a { 1 } else { 0 }
}

Logical AND

The logical AND operator && returns true if both operands are true.

The && operator uses short-circuit evaluation: if the left operand is false, the right operand is not evaluated.

fn main() -> i32 {
    if true && true { 1 } else { 0 }   // 1
    if true && false { 1 } else { 0 }  // 0
}

Logical OR

The logical OR operator || returns true if either operand is true.

The || operator uses short-circuit evaluation: if the left operand is true, the right operand is not evaluated.

fn main() -> i32 {
    if false || true { 1 } else { 0 }  // 1
    if false || false { 1 } else { 0 } // 0
}

Precedence

Operator precedence (highest to lowest):

1. ! (logical NOT)
2. && (logical AND)
3. || (logical OR)

fn main() -> i32 {
    // true || false && false => true || (false && false) => true
    if true || false && false { 1 } else { 0 }
}

Type Checking

All operands of logical operators MUST have type bool.