C :

#include <stdio.h>

int main()
{
	int n;
	scanf("%d",&n);
	int i,j;
	for(i=0;i<n;i++)
	{
		for(j=0;j<n;j++)
	printf("*");
	printf("\n");
	
	}
	
	return 0;
}

C++ :

#include <iostream>
using namespace std;
int main()
{
	int n,i,j;
	cin>>n;
	for(i=1;i<=n;i++)
	{
		for(j=1;j<=n;j++)
		{
			cout<<'*';
		}
		cout<<endl;
	}
	return 0;
}

Pascal :

var
  n,i,j:longint;
begin
  read(n);
  for i:=1 to n do
  begin
    for j:=1 to n do
    write('*');
    writeln;
  end;
end.

Java :

import java.util.Scanner;
public class Main{
    public static void main(String[] args){
        Scanner in=new Scanner(System.in);
        while(in.hasNext()){
            int n=in.nextInt();
            for(int i=0;i<n;i++){
                for(int j=0;j<n;j++){
                    System.out.print("*");
                }
                System.out.println();
            }
        }
    }
}