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Creates an instance initialized to false.

Do not call this initializer directly. Instead, use the Boolean literal false to create a new Bool instance.

Declaration

Creates an instance equal to the given Boolean value.

• Parameter value: The Boolean value to copy.

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 or 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.

• Parameter value: The value of the new instance.

Declaration

Creates a new instance by decoding from the given decoder.

This initializer throws an error if reading from the decoder fails, or if the data read is corrupted or otherwise invalid.

• Parameter decoder: The decoder to read data from.

Declaration

Creates a new Boolean value from the given string.

If the description value is any string other than "true" or "false", the result is nil. This initializer is case sensitive.

• Parameter description: A string representation of the Boolean value.

Declaration

A mirror that reflects the Bool instance.

Declaration

A custom playground Quick Look for the Bool instance.

Declaration

A textual representation of the Boolean value.

Declaration

Encodes this value into the given encoder.

This function throws an error if any values are invalid for the given encoder's format.

• Parameter encoder: The encoder to write data to.

Declaration

Hashes the essential components of this value by feeding them into the given hasher.

• Parameter hasher: The hasher to use when combining the components of this instance.

Declaration

Toggles the Boolean variable's value.

Use this method to toggle a Boolean value from true to false or from false to true.

var bools = [true, false]
 
bools[0].toggle()
// bools == [false, false]

Declaration

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!"

• Parameter a: The Boolean value to negate.

Declaration

Declaration

Performs a logical AND operation on two Boolean values.

The logical AND operator (&&) combines two Boolean 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:

Declaration

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.

Declaration

Returns a random Boolean value.

This method returns true and false with equal probability.

let flippedHeads = Bool.random()
if flippedHeads {
    print("Heads, you win!")
} else {
    print("Maybe another try?")
}

This method is equivalent to calling Bool.random(using:), passing in the system's default random generator.

Declaration

Returns a random Boolean value, using the given generator as a source for randomness.

This method returns true and false with equal probability. Use this method to generate a random Boolean value when you are using a custom random number generator.

let flippedHeads = Bool.random(using: &myGenerator)
if flippedHeads {
    print("Heads, you win!")
} else {
    print("Maybe another try?")
}

Note: The algorithm used to create random values may change in a future version of Swift. If you're passing a generator that results in the same sequence of Boolean values each time you run your program, that sequence may change when your program is compiled using a different version of Swift.

• Parameter generator: The random number generator to use when creating the new random value.

Declaration

Performs a logical OR operation on two Boolean values.

The logical OR operator (||) combines two Boolean 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:

Declaration