4.string查找和替换

#include<iostream>
using namespace std;

//1.查找
void test0401()
{
    string str1 = "abcdefgde";

    int pos1 = str1.find("de");

    cout << "pos1=" << pos1 << endl;

    int pos2 = str1.find("df");//-1未找到字符串
    cout << "pos2=" << pos2 << endl;

    //rfind和find的区别
    //1.rfind从右往左找，   find从左往右找第一个匹配的字符串
    int pos3= str1.rfind("de");
    cout << "pos3=" << pos3 << endl;

}

//2.替换
void test0402()
{
    string str1 = "abcdefg";

    str1.replace(1, 3, "1111");//从1号位置起三个字符替换为“1111”

    cout << "str1=" << str1 << endl;
}

int main()
{

    //test0401();

    test0402();

    system("pause");
    return 0;
}