C++字符串操作库函数

 #include <bits/stdc++.h>
 using namespace std;
 int main()
 {
 char s1[]="";
 char s2[]="abcdefg";
 char s3[]="ABCDE";
 strncat(s1,s2,);
 cout<<s1<<endl;///输出12345abc
 strncpy(s1,s3,);
 cout<<s1<<endl;///输出ABC45abc
 strncpy(s2,s3,);
 cout<<s2<<endl;///输出ABCDE
 cout<<strncmp(s1,s3,)<<endl;///输出0
 char *p=strchr(s1,'B');
 if(p)
 cout<<p-s1<<","<<*p<<endl;///输出1,B
 else
 cout<<"Not Found"<<endl;
 p=strstr(s1,"45a");
 if(p)
 cout<<p-s1<<","<<p<<endl;///输出3,45abc
 else
 cout<<"Not Found"<<endl;
 cout<<"strtok usage demo:"<<endl;
 char str[]="- This,a sample string,ok.";
 p=strtok(str," ,.-");
 while(p!=NULL)
 {
 cout<<p<<endl;
 ////////////输出
 /*
 This
 a
 sample
 string
 ok

 */
 p=strtok(NULL," ,.-");
 }
 return ;
 }