cout Formatting

Question

Hi, I'm pretty sure this is a simple question in regards to formatting but here's what I want to accomplish:

I want to output data onto the screen using cout. I want to output this in the form of a table format. What I mean by this is the columns and rows should be properly aligned. Example:

Test                 1
Test2                2
Iamlongverylongblah  2
Etc                  1

I am only concerned with the individual line so my line to output now(not working) is

cout << var1 << "\t\t" << var2 << endl;

Which gives me something like:

Test                 1
Test2                  2
Iamlongverylongblah         2
Etc                  1

Answer 1

I advise using Boost Format. Use something like this:

cout << format("%|1$30| %2%") % var1 % var2;

Answer 2

setw.

#include <iostream>
#include <iomanip>
using namespace std;

int main () {
  cout << setw(21) << left << "Test"  << 1 << endl;
  cout << setw(21) << left << "Test2"  << 2 << endl;
  cout << setw(21) << left << "Iamlongverylongblah"  << 2 << endl;
  cout << setw(21) << left << "Etc"  << 1 << endl;
  return 0;
}

Answer 3

You must find the length of the longest string in the first column. Then you need to output each string in the first column in a field with the length being that of that longest string. This necessarily means you can't write anything until you've read each and every string.