Summary - Advanced strings

Combine stringstream, stoi and to_string to write a CSV parser.

Summary: Parse a CSV line

In this summary we will combine istringstream, stoi and to_string to parse a CSV line. CSV separates values with commas; for example, "Alex,25,90" holds a name, age and grade.

The plan is: first use getline on an istringstream to read up to the comma, then pull the remaining two values with >>. Convert numbers with stoi, and fold the result into text with to_string. This combines different string operations in a single task.

Exercise Read name and age from a CSV line

Add the #include <sstream> header. Define istringstream iss("Alex,25");. Declare string name; and int age;. Read the name up to the comma with getline(iss, name, ',');; pull the remaining integer with iss >> age;. Print with cout << name << " - " << age << endl;.

Show example solution

#include <iostream>
#include <string>
#include <sstream>
using namespace std;

int main() {
    istringstream iss("Alex,25");
    string name;
    int age;
    getline(iss, name, ',');
    iss >> age;
    cout << name << " - " << age << endl;
    return 0;
}

Test yourself

What does getline(iss, name, ',') do?
- Reads the whole line into one string
- Reads from the stream up to a comma
- Converts a number to an integer
- Inserts a piece into a string
Show answer

Reads from the stream up to a comma — The third parameter is the delimiter; getline reads up to the comma.
Match each function with its job

istringstream

Turns string into a stream
getline

Reads up to a delimiter
stoi

Converts to integer
to_string

Converts to string

Fill in the blank: getline call

istringstream iss("Alex,30");
string name;
____(iss, name, ',');

Show answer

istringstream iss("Alex,30");
string name;
getline(iss, name, ',');

Next lesson: Defining structs

We Are Enhancing Your Experience

Cookie Preferences

Strictly Necessary Cookies

Analytical Cookies