What is a programming language?

Programming basics

A programming language is a formal computer language or constructed language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs to control the behavior of a machine or to express algorithms.

Fundamental operations of a computer

The most basic instructions a computer can be given are:

• ADD
• COMPARE
• RETRIEVE
• STORE

Compound operations

Compound operations are composed of very large numbers of fundamental operations. For example, if we wanted to multiply, we would simply add groups of numbers until we had found our solution.

If we ask a simple question: what is the biggest item on this list, we might use complex code like this:

$list_of_numbers = [12,1,54,8,19,4,13,21,12,89,-1,6]

echo max($list_of_numbers);

But the computer (using fundamental operations) will process the above instructions like this:

LOAD register 00001
ADD 12
STORE result
COMPARE result to register 0002

(...and so on until the largest number has been found and stored)

Review the ALU

In order to really understand this material, we must understand the ALU - the "brain" of the computer.

An example

Below is an example of a program language designed to communicate instructions to a machine. The piano is "fed" instructions which enable it to play a simple song. The song is an example of a program. Can you imagine how difficult it might be to "write" these instructions?!?

Explain the need for higher level languages.

If you have watched the example above, you might immediately realize it would be crazy to write a complex piano piece by punching holes in a piece of paper. This is why we use high-level languages.

We need high level languages because problems are complex.

Essential features of a programming language

• Fixed vocabulary
• Unambiguous meaning
• Consistent grammar & syntax

Standards

• State the fundamental operations of a computer.
• Distinguish between fundamental and compound operations of a computer.
• Explain the essential features of a computer language.
• Explain the need for higher level languages.
• Outline the need for a translation process from a higher level language to machine executable code.

Give a sequence of brief answers with no explanation.

A unit of abstract mathematical system subject to the laws of arithmetic.

Give a detailed account including reasons or causes.

Give a specific name, value or other brief answer without explanation or calculation.

Give a specific name, value or other brief answer without explanation or calculation.

Make clear the differences between two or more concepts or items.

Give a brief account.