C++ string数据查找、string数据替换、string子串获取

string查找示例见下，代码见下，以及对应运行结果见下：

#include<iostream>using namespace std;int main() {// 1string s1 = "hellooooworld";cout << s1.find("oooo") << endl;// 2cout << (int)s1.find("oooo", 8) << endl;cout << s1.find("oooo", 4) << endl;// 3cout << s1.find('o') << endl;cout << s1.find('o', s1.find('o') + 1) << endl;// 4 从右向左查找cout << s1.rfind("oo") << endl; }

运行结果见下：

string数据替换，代码见下：

#include<iostream>using namespace std;int main() {// 1 string s1 = "hello woooorld";s1.replace(7, 5, "or"); // 代表从第七个元素开始，取五个字符，替换成对应字符cout << s1 << endl;// 2s1 = "hello woooorld";s1.replace(s1.begin()+7, s1.begin()+12, "or"); // 这个区间是左闭右开的，所以要到12cout << s1 << endl;// 3s1 = "hello woooorld";s1.replace(s1.begin() + 7, s1.begin() + 12, "or123edafsgsrg", 2); cout << s1 << endl;}

运行结果见下

string子串获取，代码见下：

#include<iostream>using namespace std;int main() {// 1 string s1 = "hello woooorld";string sub_s1 = s1.substr(7, 4);cout << sub_s1 << endl;// 2string s2 = "xiaoxiaode&&yikeshu";int pos = s2.find("&&");string s3 = s2.substr(0, pos);cout << s3 << endl;}

运行结果见下