Difference between revisions of "Variable Names"

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* It must start with a letter or underscore.
* 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 can be followed by any number of additional upper or lower case letters, underscores, or numbers.
* It may end in a dollar sign ($).
* Variable names are case sensitive.
* Variable names are case sensitive.
* In [[NairnFEAMPMViz]], string variables must end in a dollar sign ($) while numeric variables must not. In [[NairnFEAMPM]], a variable can optionally end in a dollar sign ($) and for compatibility, it is good practice to end string variable with a dollar sign.
* In [[NairnFEAMPM]], the name cannot contain any [[Expression Syntax#Supported Functions|numeric function]] as a substring in the name.
* In [[NairnFEAMPM]], the name cannot contain any [[Expression Syntax#Supported Functions|numeric function]] as a substring in the name.
In [[NairnFEAMPM]], any variable can be a numeric or a string variable. In [[NairnFEAMPMViz]], string variables must end in a dollar sign ($) 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 ==
== Initializing a Variable ==

Revision as of 20:37, 29 August 2013

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.
  • Variable names are case sensitive.
  • In NairnFEAMPMViz, string variables must end in a dollar sign ($) while numeric variables must not. In NairnFEAMPM, a variable can optionally end in a dollar sign ($) and for compatibility, it is good practice to end string variable with a dollar sign.
  • In NairnFEAMPM, the name cannot contain any numeric function as a substring in the name.

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.