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The same very simple program in many different programming languages

Archive - Originally posted on "The Horse's Mouth" - 2010-03-31 07:32:37 - Graham Ellis

I was asked how many languages I teach yesterday - and the answer's quite a few; at times, it's almost "the more the merrier" as to a very great extent they are varieties on a theme much of the way - but different balances of features make some languages especially good for some uses.

As a geek's relaxation after some very heavy days, I have just taken a very simple example - a loop counting downwards - from yesterday's Lua course, and recoded it into a number of different languages - I'll share the code here:

In C

#include <stdio.h>
main() {
  int k;
  for (k=10; k>=1; k--) {
    printf("%d\n",k);
  }
}

C Courses - Source of this example

In C++

using namespace std;
#include <iostream>
main() {
  int k;
  for (k=10; k>=1; k--) {
    cout << k << endl;
  }
}

C++ Courses - Source of this example

In Java

public class revl {
  public static void main(String [] args) {
    int k;
    for (k=10; k>=1; k--) {
      System.out.println(k);
    }
  }

Java Courses - Source of this example

}

In Lua

for k=10,1,-1 do
  print (k)
  end

Lua Courses - Source of this example

In PHP

<?php
for ($k=10; $k>=1; $k--) {
  print ("$k\n");
  }
?>

PHP Courses - Source of this example

In Perl

for ($k=10; $k>=1; $k--) {
  print ("$k\n");
  }

Perl Courses - Source of this example

In Python

for k in range(10,0,-1):
  print k

Python Courses - Source of this example

In Ruby

for k in 1..10
  print ("#{11-k}\n")
  end

Ruby Courses - Source of this example

In Shell (works in ksh and bash)

let a=10
while [[ $a -ge 1 ]] ; do
  echo $a
  let a-=1
done

Linux / Unix / Shell Courses - Source of this example

and in Tcl

set k 10
while {$k >= 1} {
  puts $k
  incr k -1
  }

Tcl, Tk, Expect Courses - Source of this example

In Summary ... there are many ways of doing something like this in all of the languages - the examples above are not necessarily best practise, but they give you an idea of programs, loops, variables, and how they compare. I could have added Javascript, XSLT, Fortran, C Shell, Basic and perhaps a few others - but the above are just the languages I happened to have on the machine I was using - one of our teaching machines - and I could test them quickly. Did someone mention awk ...