Difference between revisions of "Variable Names"
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Variables are defined and used in the form <tt>#varname</tt> where <tt>varname</tt> 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: | Variables are defined and used in the form <tt>#varname</tt> where <tt>varname</tt> 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 must start with a letter (a-z or A-Z) or an 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 (A-Z) or lower (a-z) case letters, underscores (_), or numbers (0-9). | ||
* Variable names are case sensitive. | * Variable names are case sensitive. | ||
* In [[ | * 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 variables with a dollar sign. | ||
* In [[NairnFEAMPMViz]], the name cannot contain any [[Expression Syntax#Supported Functions|supported function name]] as a substring within the name. | |||
In [[NairnFEAMPM]], | |||
== Initializing a Variable == | == Initializing a Variable == | ||
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* The [[Expression Syntax|expression]] in the square brackets must evaluate to an integer index into the array. | * The [[Expression Syntax|expression]] in the square brackets must evaluate to an integer index into the array. | ||
* Multidimensional arrays are allowed such as <tt>#z[#i][#j]</tt> | * Multidimensional arrays are allowed such as <tt>#z[#i][#j]</tt>. | ||
* There is no need to define the dimension of arrays. | * There is no need to define the dimension of arrays. |
Latest revision as of 21:28, 14 January 2014
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 (a-z or A-Z) or an underscore (_).
- It can be followed by any number of additional upper (A-Z) or lower (a-z) case letters, underscores (_), or numbers (0-9).
- 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 variables with a dollar sign.
- In NairnFEAMPMViz, the name cannot contain any supported function name as a substring within 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.