字母大小写转换和判断（已测试）

#include <stdio.h>#define thisCharIs(ch, c) (c == (ch|32)) // 判断字母相同（不区分大小写）// 字母转换成小写void Lcase(char *ch){if (!ch) return;if (*ch >= 'A' && *ch <= 'Z')*ch |= 32;}// 字母转换成大写void Ucase(char *ch){if (!ch) return;if (*ch >= 'a' && *ch <= 'z')*ch &= ~32;}int main(int argc, char **argv){char ch, tmp;for (ch='a'; ch<='z'; ch++) {tmp = ch;Ucase(&ch);printf("%c: %c\n", tmp, ch);ch = tmp;}return 0;}

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