C++编程问题

明显能搜到的问题，请先百度/Google API文档，搜不到，可以自己写代码试，还有不懂再提问。

int toupper ( int c );

Convert lowercase letter to uppercase

Converts c to its uppercase equivalent if c is a lowercase letter and has an uppercase equivalent. If no such conversion is possible, the value returned is c unchanged.

Notice that what is considered a letter may depend on the locale being used; In the default "C" locale, a lowercase letter is any of: a b c d e f g h i j k l m n o p q r s t u v w x y z, which translate respectively to: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z.

In other locales, if a lowercase character has more than one correspondent uppercase character, this function always returns the same character for the same value of c.

In C++, a locale-specific template version of this function (toupper) exists in header .

Parameters

• c

• Character to be converted, casted to an int, or EOF.




Return Value

• The uppercase equivalent to c, if such value exists, or c (unchanged) otherwise. The value is returned as an int value that can be implicitly casted to char.