Functions

A function is a built-in algorithm that takes zero or more comma-separated arguments and returns a (possibly NULL ) result.

General Expressions

The number and type of the arguments are specific to each function and are described in the following sections for each function. In general, the arguments to a function can be any valid expression, including another function call.

[[function_name (arg1, arg2, ..., argN )]] 

Elements

Table 1. Function elements

Elements	Description
function_name	Function names begin with a letter and continue with any alphanumeric character or underscore.
argX	Any valid expression. Must match the type that is needed by the function.