C++ - 实现strcmp函数

// Compare.cpp - by Chimomo#include <iostream>class String{public:static int Compare(const char* s1, const char* s2){if (s1 == NULL || s2 == NULL){if (s1 == NULL && s2 != NULL){return -*s2;}if (s1 != NULL && s2 == NULL){return *s1;}if (s1 == NULL && s2 == NULL){return 0;}}else{while (*s1 && *s2 && *s1++ == *s2++);return *s1 - *s2;}}};

// Main.cpp - by Chimomo#include <iostream>#include "Compare.cpp"using namespace std;int main(){char s1[10] = "456456789";char * s2 = NULL;cout << String::Compare(s1, s2) << endl;return 0;}// Output:/*52*/