CODEWITHSUNDEEP
c++
user5648124
user5648124

Reputation:

How to print a string that has integers inside of it C++

I am appending an integer to a String reference called output inside a function. I made a String called output in another function and I passed it by reference an argument to the function. However when I try to print it I get a bunch of weird symbols ��������������������. I tried to use sstream for output but it didn't work:

Student.cc

void Student::makeString(string& output){
    output += fname + "\t"; // this is a string
    output += lname + "\t"; // this is a string
    output += id + "\t"; // this is an int   
}

IO.cc

void IO::printInfo(Student& student){
    string output = "";
    student.makeString(output);

    // doesnt work
    cout << output << endl;

    // doesn't work
    stringstream ss;
    ss << output;
    cout << ss.str() << endl;
}

I still get creepy characters. Help!

Upvotes: 1

Views: 588

Answers (1)

R Sahu
R Sahu

Reputation: 206697

output += id + "\t"; // this is an int

is equivalent to 

output += (id + "\t");

which is equivalent to:

char const* s1 = "\t";
char const* s2 = s1 + id;
output += s2;

Unless id is 1 or 0, that leads to accessing memory that you are not supposed to, which causes undefined behavior.

I am guessing you want to append the string representation of id plus "\t" to output. you can use:

output += std::to_string(id);
output += "\t";

Upvotes: 1

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