c - C编程:如何检查输入字符串是否包含大写和小写字母的组合

Question

我是这里的新手。如上所述，我想知道如何检查输入字符串是否包含大写和小写的组合。之后，打印一条语句以显示输入字符串包含大写和小写字母的组合。提前致谢。

Answer 1

步骤0：您需要的变数

char* str;
int   i;
char  found_lower, found_upper;

步骤1：遍历字符串

for (int i = 0; str[i] != '\0'; i++)

步骤2：检测大小写字符

found_lower = found_lower || (str[i] >= 'a' && str[i] <= 'z')
found_upper = found_upper || (str[i] >= 'A' && str[i] <= 'Z')

步骤3：合并结果

mixed_case = found_lower && found_upper

步骤4（可选）尽早脱离 for节省时间

if (found_lower && found_upper) break;

全文（警告：未经测试）：

char is_mixed(char* str) {

    int   i;
    char  found_lower = false, found_upper = false;

    for (int i = 0; str[i] != '\0'; i++) {
        found_lower = found_lower || (str[i] >= 'a' && str[i] <= 'z');
        found_upper = found_upper || (str[i] >= 'A' && str[i] <= 'Z');

        if (found_lower && found_upper) break;
    }

    return (found_lower && found_upper);

}