string 容器

构造字符串

#include <iostream>
#include <cstdio>

using namespace std;
//构造字符串
int main() {
    //solution 1
    string name="dfasf";
    const char *name1="dfdas";
    string s2(name);
    cout<<s2<<endl;
    //dfasf
    
    string s21(name1);
    cout<<s21;
    //dfdas
 
    string a123(4,'a');
    cout<<a123;
    //aaaa

    //solution 2

    return 0;
}

字符串赋值

#include <iostream>
#include <cstdio>
#include <string>

using namespace std;
//字符串赋值
int main() {
    //operator assign
    string s1;
    s1='a';
    string s2;
    s2= s1;
    cout<<s2<<endl;
    s2="dsafs";

    //function solution;
    s2.assign(s1);
    cout<<s2<<endl;

    s2.assign("dfads",2);
    cout<<s2<<endl;

    s2.assign(5,'l');
    cout<<s2<<endl;

    string s3(s2,4);
    cout<<s3;

//    string s4(4,s2) 
//    grammar false;


/*
a
a
df
lllll
l
*/
      return 0;
}

字符串的追加

#include <iostream>
#include <cstdio>
#include <string>

using namespace std;
//字符串赋值
int main() {

    string s2;
    s2.assign(5,'l');
    cout<<s2<<endl;
    s2+="dafd";
    s2+='a';
    cout<<s2<<endl;
    s2.append(s2,4,2);
    cout<<s2<<endl;
    
//"F:\clion c++\code\cmake-build-debug\code.exe"
//lllll
//llllldafda
//llllldafdald
//
//Process finished with exit code 0
    return 0;
}

字符串的查找和替换

//查找
//s2="lllllldafdald";
    //find and replace
    int pos = s2.find("ld");// find from left to right
    //return value = -1, no "ld";
    //return value = index of l ;
    cout<<pos<<endl;//4

    pos=s2.rfind("ld") ;//find from right to left;
    cout<<pos<<endl;//10
    
    //替换
    //s2="lllllldafdald";
    s2.replace(1,3,"liandashuaibi");
    //从字符串的位置1起，3个字符替换为后面的字符串;
    cout<<s2<<endl;
    //lliandashuaibildafdald;

字符串之间的比较

 string s3(s2,4,2);
    cout<<s3<<endl;//s3=nd;
    cout<<s3.compare(s2)<<endl;//1
    cout<<s2.compare(s2)<<endl;//0
    cout<<s2.compare(s3)<<endl;//-1

字符串访问字符

 cout<<s2.at(2)<<endl;
    cout<<s2[2];
   

字符串删除插入元素

s2.insert(1,"#$!1");
    cout<<s2<<endl;
    s2.erase(2,3);
    cout<<s2<<endl;
    /*
il#$!1liandashuaibildafdald
l#liandashuaibildafdald*/