JavaScript Identifiers

All JavaScript variables must be identified with unique names. These unique names are called identifiers. JavaScript identifiers are case-sensitive. These identifiers can be short names (like x and y), or more descriptive names (eg: age, sum, totalVolume). The general rules for constructing names for variables (unique identifiers) are:

• Names can contain letters, digits, underscores, and dollar signs.
• Names must begin with a letter
• Names can also begin with $ and _ (but we will not use these in this tutorial)
• Names are case sensitive ( y and Y are different variables)
• Reserved words cannot be used as names (such as the JavaScript keywords)