auto Keyword

 

The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at auto Keyword.

The auto keyword is a declaration specifier. However, the C++ standard defines an original and a revised meaning for this keyword. Before Visual C++ 2010, the auto keyword declares a variable in the automatic storage class; that is, a variable that has a local lifetime. Starting with Visual C++ 2010, theauto keyword declares a variable whose type is deduced from the initialization expression in its declaration. The /Zc:auto[-] compiler option controls the meaning of the auto keyword.

auto declarator ;  
auto declarator initializer;  

The definition of the auto keyword changes in the C++ programming language, but not in the C programming language.

The following topics describe the auto keyword and the corresponding compiler option:

(NOTINBUILD)Storage-Class Specifiers
Keywords

Show: