Identifiers

Identifiers are merely names for variables and functions. Programmers must know the names of built in variables and functions to use them in scripts and must know some rules about identifiers to define their own variables and functions. The following rules are simple and intuitive.

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Identifiers may use only ASCII letters, upper or lower case, digits, the underscore, "_", and the dollar sign, "$". That is, they may use only characters from the following sets of characters.
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789"
"_$"

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Identifiers may not use the following characters.
"+<>&|=!*/%^~?:{};()[].'"`#,"

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Identifiers must begin with a letter, underscore, or dollar sign, but may have digits anywhere else.

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Identifiers may not have white space in them since white space separates identifiers for the interpreter.

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Identifiers may be as long a programmer needs.

The following identifiers, variables and functions, are valid:

Sid

Nancy7436

annualReport

sid_and_nancy_prepared_the_annualReport

$alice

CalculateTotal()

$SubtractLess()

_Divide$All()

The following identifiers, variables and functions, are not valid:

1sid

2nancy

this&that

Sid and Nancy

ratsAndCats?

=Total()

(Minus)()

Add Both Figures()

Prohibited identifiers

Identifiers to avoid

Variables

Variable scope

Function identifier

Function scope