C++中string查找和取子串和整形转化

1.string.find函数

 #include <iostream>

 #include <string>

 using namespace std;

 /* run this program using the console pauser or add your own getch, system("pause") or input loop */

 int main(int argc, char** argv) {

     string s;

     string str;

     char *p = "abc";

     int index;

     getline(cin,s);

     cout<<"s="<<s<<endl;

     getline(cin,str);

     cout<<"str="<<str<<endl;

     index = s.find(str);

     cout<<"char index="<<index<<endl;

     index = s.find(p);

     cout<<"string index="<<index<<endl;

     return ;

 }

2. 取子串

#include <iostream>

#include <string>

#include <vector>

#include <stdlib.h>

using namespace std;

//输入2015-10-22

int riqi(string str){

    int i = ;

    int year;

    int month;

    int day;

    int i_start,i_end;

    string tmp;

    i_start = str.find("-");//第一个'-'

    tmp = str.substr(,i_start);//取从0下标开始的i_start个字符

    year = atoi(tmp.c_str());//tmp.c_str()转化为C语言中字符串指针

    i_end = str.rfind("-");//最后一个'-'

    tmp = str.substr(i_start+,i_end - i_start);

    month = atoi(tmp.c_str());

    tmp = str.substr(i_end+);

    day = atoi(tmp.c_str());

    cout<<year<<" "<<month<<' '<<day<<endl;

    //输出的结果为  2015 10 22

    return ;

}