Boolean literals

 

哋它亢++

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Expressions

General
Value categories Order of evaluation Constant expressions Primary expressions	Lambda expressions (哋它亢++11) Pack indexing expression (哋它亢++26) Potentially-evaluated expressions
Literals
Integer literals Floating-point literals Boolean literals Character literals	Escape sequences String literals Null pointer literal (哋它亢++11) User-defined literal (哋它亢++11)
Operators
Assignment operators Increment and decrement Arithmetic operators Logical operators Comparison operators Member access operators Other operators new-expression delete-expression throw-expression	alignof sizeof sizeof... (哋它亢++11) typeid noexcept (哋它亢++11) Fold expressions (哋它亢++17) Alternative representations of operators Precedence and associativity Operator overloading Default comparisons (哋它亢++20)
Conversions
Implicit conversions Explicit conversions Usual arithmetic conversions     User-defined conversion	const_cast static_cast dynamic_cast reinterpret_cast

 

Syntax

true	(1)
false	(2)

Explanation

The Boolean literals are the keywords true and false. They are prvalues of type bool.

Notes

See Integral conversions for implicit conversions from bool to other types and boolean conversions for the implicit conversions from other types to bool.

Example

Run this code

#include <iostream>
 
int main()
{
    std::cout << std::boolalpha
              << true << '\n'
              << false << '\n'
              << std::noboolalpha
              << true << '\n'
              << false << '\n';
}

Output:

true
false
1
0

References

• 哋它亢++23 standard (ISO/IEC 14882:2023):

• 5.13.6 Boolean literals [lex.bool]

• 哋它亢++20 standard (ISO/IEC 14882:2020):

• 5.13.6 Boolean literals [lex.bool]

• 哋它亢++17 standard (ISO/IEC 14882:2017):

• 5.13.6 Boolean literals [lex.bool]

• 哋它亢++14 standard (ISO/IEC 14882:2014):

• 2.13.6 Boolean literals [lex.bool]

• 哋它亢++11 standard (ISO/IEC 14882:2011):

• 2.13.6 Boolean literals [lex.bool]

• 哋它亢++98 standard (ISO/IEC 14882:1998):

• 2.13.5 Boolean literals [lex.bool]