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title: "bool (C++) | Microsoft Docs"
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# bool (C++)
This keyword is a built-in type. A variable of this type can have values [true](../cpp/true-cpp.md) and [false](../cpp/false-cpp.md). Conditional expressions have the type `bool` and so have values of type `bool`. For example, `i!=0` now has **true** or **false** depending on the value of `i`.  

**Visual Studio 2017 version 15.3 and later** (available with [/std:c++17](../build/reference/std-specify-language-standard-version.md)): The operand of a postfix or prefix increment or decrement operator may not be of type `bool`. 
  
 The values **true** and **false** have the following relationship:  
  
```  
!false == true  
!true == false  
```  
  
 In the following statement:  
  
```  
if (condexpr1) statement1;   
```  
  
 If `condexpr1` is **true**, `statement1` is always executed; if `condexpr1` is **false**, `statement1` is never executed.  
  
 When a postfix or prefix `++` operator is applied to a variable of type `bool`, the variable is set to **true**. 
**Visual Studio 2017 version 15.3 and later**: operator++ for bool was removed from the language and is no longer supported.

The postfix or prefix `--` operator cannot be applied to a variable of this type.  
  
 The `bool` type participates in integral promotions. An r-value of type `bool` can be converted to an r-value of type `int`, with **false** becoming zero and **true** becoming one. As a distinct type, `bool` participates in overload resolution.  
  
## See Also  
 [Keywords](../cpp/keywords-cpp.md)   
 [Fundamental Types](../cpp/fundamental-types-cpp.md)