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Creates an instance initialized to false.

Don't call this initializer directly. Instead, use the Boolean literal false to create a new Bool instance.

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[Foundation]

Declaration

Creates an instance initialized to the specified Boolean literal.

Do not call this initializer directly. It is used by the compiler when you use a Boolean literal. Instead, create a new Bool instance by using one of the Boolean literals true and false.

var printedMessage = false
 
if !printedMessage {
    print("You look nice today!")
    printedMessage = true
}
// Prints "You look nice today!"

In this example, both assignments to the printedMessage variable call this Boolean literal initializer behind the scenes.

value: The value of the new instance.

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Instantiates an instance of the conforming type from a string representation.

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A mirror that reflects the Bool instance.

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A custom playground Quick Look for this instance.

If this type has value semantics, the PlaygroundQuickLook instance should be unaffected by subsequent mutations.

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A textual representation of the Boolean value.

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The hash value for the Boolean value.

Two values that are equal always have equal hash values.

Note: The hash value is not guaranteed to be stable across different invocations of the same program. Do not persist the hash value across program runs. See Also: Hashable

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Performs a logical NOT operation on a Boolean value.

The logical NOT operator (!) inverts a Boolean value. If the value is true, the result of the operation is false; if the value is false, the result is true.

var printedMessage = false
 
if !printedMessage {
    print("You look nice today!")
    printedMessage = true
}
// Prints "You look nice today!"

a: The Boolean value to negate.

Declaration

Performs a logical AND operation on two Bool values.

The logical AND operator (&&) combines two Bool values and returns true if both of the values are true. If either of the values is false, the operator returns false.

This operator uses short-circuit evaluation: The left-hand side (lhs) is evaluated first, and the right-hand side (rhs) is evaluated only if lhs evaluates to true. For example:

let measurements = [7.44, 6.51, 4.74, 5.88, 6.27, 6.12, 7.76]
let sum = measurements.reduce(0, combine: +)
 
if measurements.count > 0 && sum / Double(measurements.count) < 6.5 {
    print("Average measurement is less than 6.5")
}
// Prints "Average measurement is less than 6.5"

In this example, lhs tests whether measurements.count is greater than zero. Evaluation of the && operator is one of the following:

• When measurements.count is equal to zero, lhs evaluates to false and rhs is not evaluated, preventing a divide-by-zero error in the expression sum / Double(measurements.count). The result of the operation is false.
• When measurements.count is greater than zero, lhs evaluates to true and rhs is evaluated. The result of evaluating rhs is the result of the && operation.

Parameters: lhs: The left-hand side of the operation. rhs: The right-hand side of the operation.

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Returns a Boolean value indicating whether two values are equal.

Equality is the inverse of inequality. For any values a and b, a == b implies that a != b is false.

Parameters: lhs: A value to compare. rhs: Another value to compare.

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Performs a logical OR operation on two Bool values.

The logical OR operator (||) combines two Bool values and returns true if at least one of the values is true. If both values are false, the operator returns false.

This operator uses short-circuit evaluation: The left-hand side (lhs) is evaluated first, and the right-hand side (rhs) is evaluated only if lhs evaluates to false. For example:

let majorErrors: Set = ["No first name", "No last name", ...]
let error = ""
 
if error.isEmpty || !majorErrors.contains(error) {
    print("No major errors detected")
} else {
    print("Major error: \(error)")
}
// Prints "No major errors detected")

In this example, lhs tests whether error is an empty string. Evaluation of the || operator is one of the following:

• When error is an empty string, lhs evaluates to true and rhs is not evaluated, skipping the call to majorErrors.contains(_:). The result of the operation is true.
• When error is not an empty string, lhs evaluates to false and rhs is evaluated. The result of evaluating rhs is the result of the || operation.

Parameters: lhs: The left-hand side of the operation. rhs: The right-hand side of the operation.

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