C语言字符串统计：长度、大小写字母和数字数量

#include <stdio.h>\n\nint main() {\n char str[100];\n int len = 0;\n int uppercase = 0;\n int lowercase = 0;\n int digits = 0;\n\n printf("请输入一个字符串：");\n scanf("%s", str);\n\n // 计算字符串长度\n while (str[len] != '\0') {\n len++;\n }\n\n // 统计英文大写字母、小写字母和数字字符的数量\n for (int i = 0; i < len; i++) {\n if (str[i] >= 'A' && str[i] <= 'Z') {\n uppercase++;\n }\n else if (str[i] >= 'a' && str[i] <= 'z') {\n lowercase++;\n }\n else if (str[i] >= '0' && str[i] <= '9') {\n digits++;\n }\n }\n\n printf("字符串的实际长度：%d\n", len);\n printf("英文大写字母的数量：%d\n", uppercase);\n printf("小写字母的数量：%d\n", lowercase);\n printf("数字字符的数量：%d\n", digits);\n\n return 0;\n}