programming-for-dummies

Chapter 3: Manipulating Data
In This Chapter
Using assignment and math operators
Understanding string manipulation
Using comparison and Boolean operators
Performing data type conversions
Every program accepts data from the outside world, manipulates that
data in some way, and then calculates a useful result. Data can be
✦ Numbers
✦ Text
✦ Input from a keyboard, controller, or joystick (for a video game)
To manipulate numbers, computers can perform a variety of mathematical
operations, which is just a fancy way of saying a computer can add, subtract,
multiply, and divide. To manipulate text (or strings, as in “text strings”),
computers can perform a variety of string manipulation operations, which
can chop out a letter of a word or rearrange the letters that make up a word.
Every programming language provides built-in commands (operators) for
manipulating numbers and strings, but some programming languages are
better at manipulating numbers (or strings) than others.
For example, FORTRAN is specifically designed to make scientific calculations
easy, so FORTRAN has more operators for mathematical operations
than a language such as SNOBOL, which was designed primarily for manipulating
text strings. You can still manipulate strings in FORTRAN or calculate
mathematical equations in SNOBOL; however, you need to write a lot more
commands to do so.