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--- c:c_variables [2021/02/10 16:30] – peter
+++ c:c_variables [2021/02/10 16:37] (current) – peter
@@ Line 1: / Line 1: @@
 ====== C - C++ Variables ======
-^Type^Example^Comment^
+^Type^Example^Usage^Comment^
-|int|1| |
+|int|1|<nowiki>[<signed | unsigned>] [<short | long | long long>] int</nowiki>| |
 |long int|1L| |
 |long long int|1LL| |
-|double|1.0| |
+|double|1.0|<nowiki>[long] double</nowiki>| |
 |float|1.0F| |
-|char|'1'| |
+|char|'1'|<nowiki>[<signed | unsigned >]char</nowiki>| |
 |char*|"a string"|Automatically terminated with a null character.|
-|wchar_t*|L"a string"| |
+|wchar_t*|L"a string"|<nowiki>[<signed | unsigned >]wchar_t</nowiki>| |
 |char8_t*|u8"this is a UTF-8 string with a UTF-8 character: u2018"| |
 |char16_t*|u"this is a UTF-16 string with a UTF-16 character: u2018"| |
@@ Line 22: / Line 22: @@
 Declarations use both intrinsic and user-defined types. The intrinsic types are:
+<code c++>
 [<signed | unsigned >]char
 [<signed | unsigned >]wchar_t
@@ Line 28: / Line 29: @@
 [long] double
 bool
+</code>
+----
+The keyword **auto** can be used if C++ can determine the type of variable itself:
+<code>
+auto var = 1L;               // The type of var is long int.
+</code>
+----
+The keyword **decltype** extracts the type of an expression.
+This type can then be used wherever a type name is used.
+For example, the following example uses decltype to declare a second variable with same type as an existing variable:
+<code>
+decltype(var1) var2;         // The type of var2 is the same as var1.
+</code>