BubbleSort-String Comparison

[FranciscoSAW]

Hi. I am a beginner in C++. I was trying to make a function in a program that would read strings from a vector and would sort them by length. I thought that the comparison in strings would compare the lenghts of different strings, but it does not do that. My doubt is: What does the comparison of strings do? Does it compare the first char of the strings? Does it compare lengths? Or neither?

#include <iostream>
#include <vector>
#include <string>

using namespace std;


void bubblesort(vector<string> &v)
{
	int i = 1; 
	int iteration = v.size(); //iteration will decrease by one because after one iteration of the bubblesort the last one should already be sorted
	
	while(iteration != 1)
	{
		for (i; i < iteration; i++)
		{
		    string nome_atual = v.at(i); //current name
		    string nome_anterior = v.at(i - 1);//name before

			if (nome_atual < nome_anterior)  // comparison
			{
                            //switching the names if out of order
				v.at(i) = nome_anterior; 
				v.at(i - 1) = nome_atual;
			}
		}

		iteration--; //decreasing the iteration
		i = 1; //reset the counter that will go through the vector
	}

Right now this is sorting by alphabethical order. I want to sort by length. Any help would be great! :)
Thank you for your time!

[jonnin]

the built in string comparison is sorting by alphabet, like how a dictionary is ordered from aardvark to zoo

you should sort off

stringvar.length() < otherstring.length()

[FranciscoSAW]

So then, when comparing strings, it compares from character to character until it finds different characters or one of the strings end? Is that it?

[Thomas1965]

There is an easier way to sort your strings:

int main()
{
  vector<string> names = {"Anna", "Elisabeth", "Molly", "Debbie"};
  //#include <algorithm>
  sort(names.begin(), names.end(), [](const string& s1, const string& s2)
  {
    return s1.length() < s2.length();
  });

  for (const string& s: names)
  {
    cout << s << "\n";
  }
  return 0;
}

[jonnin]

yes, it compares them character by character using the ascii table's numeric values to sort. A is not the same as a, either, and I think b > Z due to the capitalization. If they are all first letter caps, rest not, or all lower, or all upper, or any other matching pattern like that, it will work as a dictionary. If not, you may not like the results and may want to force them all upper or all lower first.