Detailed usage of insert() function in C++string

Insert the string str before the character subscripted as pos in the original string

basic_string& insert (size_type pos, const basic_string& str);

The n characters counted from the subscript pos1 of str are inserted before the character subscript pos in the original string

basic_string& insert (size_type pos, const basic_string& str, size_type pos1, size_type n);

Insert n characters c before the character subscripted as pos in the original string

basic_string& insert (size_type pos, size_type n, char c);

Code:

#include<iostream>
using namespace std;
int main()
{
    
    
    string str="hello";
    string s="Hahah";
    str.insert(1,s);//在原串下标为1的字符e前插入字符串s
    cout<<str<<endl;

    string str1="hello";
    char c='w';
    str1.insert(4,5,c);//在原串下标为4的字符o前插入5个字符c
    cout<<str1<<endl;

    string str2="hello";
    string s2="weakhaha";
    str2.insert(0,s2,1,3);//将字符串s2从下标为1的e开始数3个字符，分别是eak，插入原串的下标为0的字符h前
    cout<<str2<<endl;

    return 0;
}

operation result:

Original link:

Insert() insert function in C++ string