C++中atoll函数的使用示例有哪些

1. 将字符串转换为长整型数值：

#include <iostream>
#include <cstdlib>

int main() {
    const char* str = "1234567890";
    long long num = atoll(str);
    
    std::cout << "Converted number: " << num << std::endl;
    
    return 0;
}

2. 处理带符号的字符串：

#include <iostream>
#include <cstdlib>

int main() {
    const char* str = "-9876543210";
    long long num = atoll(str);
    
    std::cout << "Converted number: " << num << std::endl;
    
    return 0;
}

3. 处理错误的输入情况：

#include <iostream>
#include <cstdlib>

int main() {
    const char* str = "abcd1234";
    char* endptr;
    long long num = atoll(str);
    
    if (*endptr != '\0') {
        std::cerr << "Error converting string to long long" << std::endl;
    } else {
        std::cout << "Converted number: " << num << std::endl;
    }
    
    return 0;
}