Introduction to Computing Fall 2015     Syllabus

Why are there so many programming languages?

I found the best and shortest answer on Reddit:

"Same reason why you have a fork, a knife and a spoon. Some things are better for some tasks then others. Not only that, but people who are very good with computers sometimes think, "I bet I can make something that is even better then a knife at slicing cheese!" and comes up with a cheese slicer. Then another person thinks: "I like the fork, knife and spoon, but they take up too much space." So they invent the spork.

So there are a lot of languages that have their own specialization. So it's better to write scientific programs in R and web applications in Javascript."

What are the most popular languages?

Languages are about trade-offs

Why so many languages?

Some are easier to learn

  • C++
#include <iostream.h>

int main()
    std::cout << "Hello, world!\n";
  • Javascript
Hello World in JavaScript
    document.write ("Hello, world!")
  • Python
print("Hello world!")

Languages are modified to make them 'better' in some way

  • E.g., Python3 made functions more consistent print "Hello, World!" vs. print("Hello, World!")

  • Functionality is added over time, and new languages are born.

  • 'Better' is inherently subjective and fierce debates ensue.

    • Some languages (e.g., Julia) try to make this objective by, say, saying they are faster.
    • Still debates continue.


  • High-level languages aim to have large reusable chunks
  • New languages can have additional levels of abstraction.
    • E.g., C++ introduced more support for object-oriented programming and generic programming over C. Initially, C was a subset of C++, but they have increasingly diverged over time.

New Infrastructure

  • What computers can do is greatly influenced by the technological capabilities of the time.
  • This usually means new levels of abstraction to help deal with the hardware
    • E.g., new assembly language to deal with move from 16 bit to 32 bit processors
    • node.js, which is a scaleable framework for handling many concurrent web connections
  • For scientific computing, we have to deal with connections to databases and HPC


  • Most of the time you will be either re-using code or looking up solutions online.
  • The path of least resistance for solving a particular problem.
  • We use R not because it is a particularly elegant or high performance language, but because of its many useful scientific libraries.

What does this mean for you?

  • On a daily basis, I use these languages: R, Python, SQL, awk, bash. Why?
  • You can actually call functions in other languages using bridges.


Let us Google that for you: