Variables, expressionss, and statements. [April 26, 2011, 12:34 a.m.]

Lets look at three components of many programming languages.

Three primary tools we will be working with are:

Statements - small parts of a program that do not necessarily return a result. A program is formed by a sequence of one or more statements.
Names (a.k.a. variables) - pointers to data stored in memory.
Expressions - combination of names, symbols, functions, and/or operators that return another value.

These three aspects are fundamenal to programming in general and will be explored throughout this course.

Examples:
In Python, statements can take many forms and work with many programming elements. For example assigning a name to a value:

a_name = value

Names are labels that point to a specific item in the computer's memory. With the above example a_name points to the memory location of value.

Expressions are a subset of statements and typically return some result. Basic examples of expressions include arithmetic operations:
2 + 3
3 - 2
5 * 5
10 / 5

Operators are included in expressions and consist of symbols such as +, -, /, *, **, etc.