C++ string operations behave strange

Question

Why str4 here give me like that result?
https://code.sololearn.com/cFD8d8Jui7fZ/?ref=app

Answer 1

Yes. so There is no need to use str3, str4. They works as dublicates..

You're welcome..

Answer 2

//hope it helps.. Read comments.. Mustafa Emad

#include <iostream>
using namespace std;

int main() {
string str1, str2;

getline(cin, str1); // first
getline(cin, str2); //second

string str3 = str1.append(" " + str2); // apends " "+str2 to str1 and returns new str1
// so now str1= "first second"
//str3 = "first second"
//str2 = "second"

cout << str3.length() << endl << str3 << endl;

str1.swap(str2); //swaps str1,str2 so then str1= "second" , str2="first second"

string str4 = str1.append(" " + str2); //appends str2 ("first second") to str1("second") and then returns new str1
//so now str1="second first second"
//str4 = "second first second"
//str2 = "first second"

cout << str4.length() << endl << str4 << endl;

return 0;
}

Answer 3

Jayakrishna🇮🇳 so append didn't affect on variable only but all the coming code that's help thanks I got it

Answer 4

What result? What strange you found?
can you detail it!!!

Answer 5

Jayakrishna🇮🇳 make additional text at second append

Answer 6

Mustafa Emad I run it and all fine.
Add your try with input and output and expected output.. So I can understand your doubt..!

Answer 7

Jayakrishna🇮🇳 the code is expected that:
first
second
second
first
but output is:
first
second
second
first second