1.string构造函数
string(); //创建一个空的字符串,例如:string str;
string(const char* s); //使用字符串s初始化
string(const string& str);//使用一个string对象初始化另一个string对象
string(int n,char c); //使用n个字符c初始化
#include <iostream>
using namespace std;
#include <string>
void test01(){
string s1;
cout<<"str1= "<<s1<<endl;
const char* str="hello world";
string s2(str);
cout<<"str2= "<<s2<<endl;
string s3(s2);
cout<<"str3= "<<s3<<endl;
string s4(10,'a');
cout<<"str4= "<<s4<<endl;
}
int main()
{
test01();
return 0;
}
2.string赋值操作(一般用operator= 这种方式)
给string字符串进行赋值
string& operator=(const chars); //char类型字符串 赋值给当前字符串
string& operator=(const string& s); //把字符串s赋给当前字符串
string& operator=(char c); //字符赋值给当前的字符串
string& assign(const char *s); //把字符串s赋值给当前的字符串
string& assign(const char *s,int n); //把字符串s的前n个字符赋给当前的字符串
string& assign(const string &s); //把字符串s赋给当前字符串
string& assign(int n,char c); //用n个字符c赋给当前的字符串
#include <iostream>
using namespace std;
#include <string>
void test01(){
string s1="hello world";
cout<<"str1= "<<s1<<endl;
string s2=s1;
cout<<"str2= "<<s2<<endl;
string s3;
s3='a';
cout<<"str3= "<<s3<<endl;
string s4;
s4.assign("hello c++");
cout<<"str4= "<<s4<<endl;
string s5;
s5.assign("hello c++",5);
cout<<"str5= "<<s5<<endl;
string s6;
s6.assign(s5);
cout<<"str6= "<<s6<<endl;
string s7;
s7.assign(10,'a');
cout<<"str7= "<<s7<<endl;
}
int main()
{
test01();
return 0;
}
3.字符串拼接
实现在字符串末尾拼接字符串
string& operator+=(const char* str); //重载+=操作符
string& operator+=(const char c); //重载+=操作符
string& operator+=(const string& str); //重载+=操作符
string& append(const char *s); //把字符串s连接到当前字符串结尾
string& append(const char *s,int n); //把字符串s的前n个字符连接到当前字符串结尾
string& append(const string &s); //同operator+=(const string& str)
string& append(const string &s,int pos,int n);//字符串s从pos开始的n个字符连接到字符串结尾
#include <iostream>
using namespace std;
#include <string>
void test01(){
string str1="我";
str1+="爱学习";
cout<<str1<<endl;
str1 +=':';
cout<<str1<<endl;
string str2="c/c++";
str1+=str2;
cout<<str1<<endl;
string s1="I";
s1.append(" love ");
cout<<s1<<endl;
s1.append("study abc",6);
cout<<s1<<endl;
//s1.append(str2);
//cout<<s1<<endl;
s1.append(str2,2,3);
cout<<s1<<endl;
}
int main()
{
test01();
return 0;
}