How to use toupper in C language

toupper() function converts lowercase letters to uppercase letters. Syntax: int toupper(int c) Parameters: c - the character to be converted Return value: uppercase letter or c itself is only valid for letters in the ASCII character set locale-aware, the conversion may vary depending on the locale

Usage of toupper() function in C language

##Usage of toupper() function:

The toupper() function converts lowercase letters to uppercase letters.

Syntax:

<code class="c">int toupper(int c);</code>

Parameters:

c: The characters to be converted.

Return value:

If c is a lowercase letter, returns the uppercase version; otherwise, returns c itself.

Example:

<code class="c">char c = 'a';
char upper = toupper(c);

printf("小写字母 %c 的大写字母是 %c\n", c, upper);</code>

Output:

<code>小写字母 a 的大写字母是 A</code>

Notes:

toupper() function is valid for letters in the ASCII character set.
• For non-alphabetic characters, the toupper() function will not convert.
• Thetoupper() function is locale-aware, which means that the conversion may vary depending on the current locale setting.

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