JavaScript Function Syntax

A JavaScript function is defined with:

1. The keyword: function
2. A name -- function names can contain letters, digits, underscores, and dollar signs (same rules as variables).
3. Parentheses () -- which may include parameter names separated by commas: (parameter1,  parameter2, ...).
4. Then curly brackets {}, which contain the code to be executed by the function.

• Function parameters are the names listed in the function definition
• Function arguments are the real values received by the function when it is invoked
• Inside the function, the arguments behave as local variables

A Function is much the same as a Procedure or a Subroutine, in other programming languages.