c++ string

c++

string操作

#include <string>
using namespace std;
//使用字符串初始化
string s1 = "abc";
//arr[3]最多只能有两个字符，最后一个为'\0'
char arr[3] = {"1","2","\0"};
string s2 = arr;
//替换函数，不一定要匹配长度
s.replace(1,5,"abc");
//逆置函数，在s上面逆置
reverse(s.begin(),s.end());
//当前字符串大小
cout << s1.size() << endl;
//当前字符串长度
cout << s2.length() << endl;
//string和string拼接
string s3 = s1 + s2;
//string和char拼接
string s4 = s1.append(ch,3);
cout << s4 << endl;
//string的插入，在第0个元素前面插入
cout << s4 << endl;
s4 = s4.insert(0,"2");
cout << s4 << endl;
//string元素的删除，
string::iterator it=s4.begin();
//从第1个元素开始，擦除4个元素
s4.erase(1, 4);
//删除区间[0,2)的元素
s4.erase(it,it+2)
cout << s4 << endl;
//string类型比较，结果返回0/1
cout << (s1 == s2) << endl;
cout << (s1 < s2) << endl;
cout << (s1 > s2) << endl;
//数字转为string，int不能转化
long i = 1;
s1 = to_string(i);
cout << s1 << endl;
//string转换为int, double
s1 = "123";
int x = stoi(s1);
cout << x << endl;
s1 = "123.123";
double y = stod(s1);
cout << y << endl;

总结string 的 常用操作：