Data Declarations


Variable identifiers should be lowercase with each word after the first capitalized. Here are some examples:

width, hourlyWage, totalCostPerBox

Constant identifiers should be uppercase with words separated by an underscore character. Here are some examples:


Identifiers can also contain digits (0..9) but don't use digits unless you have a compelling reason to do so.

Variable Declaration

A variable corresponds to a location in memory whose value is subject to change. To declare a variable, you must specify what type of data the variable is to represent and the name of the variable (its identifier).

Syntax:  type variableName;
Example:  int quantity;

If you want, you can give a variable its initial value at the same time it is declared.

Syntax:  type variableName = initialValue;
Example:  int quantity = 0;

Constant Declaration

A constant corresponds to a location in memory whose value cannot be changed. Use a declared constant if the value is needed two or more times or if naming the value would make your code more readable. The only difference between a variable declaration and a constant declaration is that a constant declaration begins with the keyword "const" and must include the value of the constant:

Syntax:  const type constantName = constantValue;
Example:  const double PI = 3.14159265358979;