Variable Names

The scripting language can define variables in command files and do calculations on variables using expressions.

Defining Variables

Variables are defined and used in the form #varname where varname is any valid variable name. A number sign must always be used to indicate a variable (although the number sign is optional in NairnFEAMPMViz, it is recommended to use it for compatibility). The rules for a valid variable name after the number sign (or entire name if number sign omitted in NairnFEAMPMViz) are:

• It must start with a letter or underscore.
• It can be followed by any number of additional upper or lower case letters, underscores, or numbers.
• It may end in a dollar sign ($).
• Variable names are case sensitive.
• In NairnFEAMPM, the name cannot contain any numeric function as a substring in the name.

In NairnFEAMPM, any variable can be a numeric or a string variable. In NairnFEAMPMViz, string variables must end in a dollar sign ($) and numeric variables cannot end in a dollar sign. For compatibility of scripting commands, good practice when using NairnFEAMPM is to end string variables with a dollar sign ($).

Initializing a Variable

A variable is initially defined in an assignment statement such as:

#x=1

where the variable is set equal to the right side of the equals sign which can be any valid expression. A variable cannot be used in an expression until it has been defined.

Variable Arrays

Any valid variable name can be a variable array by following it with an expression in square brackets

#y[#j]=1

where

• The expression in the square brackets must evaluate to an integer index into the array.
• Multidimensional arrays are allowed such as #z[#i][#j]
• There is no need to define the dimension of arrays.