The demise of Apple founder Steve Jobs has dominated the news. But around the same time, two lesser known geniuses also died - Dennis Ritchie, the inventor of the "C" programming language and the UNIX operating system used on most computers including the Apple iPhone, and John McCarthy, known as the father of "Artificial Intelligence" (also used in iPhones) and inventor of the "Lisp" programming language.

Let's take this opportunity to learn about computer programming languages.

Computer Programming Languages

John McCarthy

 

Dennis Ritchie

We all know how powerful computers are, and how fast they perform repeated tasks tirelessly. But in reality, a computer is actually quite dumb - a real human has to tell the computer precisely what to do using a programming language. 

Unlike the English language, a programmer who tells a computer what to do has to be very precise and detailed - there cannot be any room for misinterpretation. That is why a computer program can sometimes look very complicated and difficult to understand. But of course, once the computer understands what to do (say, if you ask it to add 10,000 numbers), it can do it in less than 1/100th of a second, whereas you may get tired after adding up just 10 of those numbers!

A "Hello World" Program

Let's take an example, written in Dennis Ritchie's "C" programming language - a program to print the sum of numbers from 1 to 10,000. Note that there are English comments to make it easy for other humans to understand. The computer doesn't understand English, but eagerly gobbles up the rest.

	main()
{
    // Comment : "sum" is a "variable"
    int sum = 0;

    // Comment : Loop through numbers from 1 to 10,000; 
    // Comment : Add one number each time
    for (int number = 1; number <= 10000; number = number + 1) {
      sum = sum + number;             
    }

    // Comment : Print out the sum
    printf ("Hello World, the sum is: %d\n", sum);
}

Easy? Programming a game like Angry Birds probably required more than 100,000 lines like these!

Why do we need many languages?

Just as there are thousands of human languages, there are tens of computer languages for many specialized purposes. Some languages used today are: C++, Objective C, Java, Python, Ruby, Javascript, and Visual Basic. Just like human languages disappear, some older ones like C, Lisp or Fortran are not used as much today, but they played important roles in the history of computing.

PHP, Python and Ruby are often used for creating web sites. Javascript is used to make those cool animation effects you often see on web sites (For example, Youngzine uses PHP and Javascript). Java and C++ are used for serious computer programs that, for example, predict the weather, or help fight wars. 

A cool first language for you to learn would be Javascript, Python or PHP. In High school, you can learn Ruby, Java or C++.