Constants
Description:
Constants are numbers (including booleans) or strings which cannot be changed after they are defined. For example, 5 will always mean the same number.
In FreeBASIC, a constant definition differs from a variable definition by usage of the Const command.
Such constants are then available globally, meaning that once defined, you can use the word to refer to a constant anywhere in your program.
After being defined with the Const command, constants cannot be altered. If code tries to alter a constant, an error message will result upon code compilation.
In FreeBASIC, a constant definition differs from a variable definition by usage of the Const command.
Such constants are then available globally, meaning that once defined, you can use the word to refer to a constant anywhere in your program.
After being defined with the Const command, constants cannot be altered. If code tries to alter a constant, an error message will result upon code compilation.
Examples:
Declare Sub PrintConstants ()
Const FirstNumber = 1
Const SecondNumber = 2
Const FirstString = "First string."
Const FirstBoolean = False
Const SecondBoolean = True
Print FirstNumber, SecondNumber 'This will print 1 2
Print FirstString 'This will print First string.
Print FirstBoolean, SecondBoolean 'This will print false true
Print
PrintConstants ()
Sub PrintConstants ()
Print FirstNumber, SecondNumber 'This will also print 1 2
Print FirstString 'This will also print First string.
Print FirstBoolean, SecondBoolean 'This will also print false true
End Sub
Const FirstNumber = 1
Const SecondNumber = 2
Const FirstString = "First string."
Const FirstBoolean = False
Const SecondBoolean = True
Print FirstNumber, SecondNumber 'This will print 1 2
Print FirstString 'This will print First string.
Print FirstBoolean, SecondBoolean 'This will print false true
PrintConstants ()
Sub PrintConstants ()
Print FirstNumber, SecondNumber 'This will also print 1 2
Print FirstString 'This will also print First string.
Print FirstBoolean, SecondBoolean 'This will also print false true
End Sub
See also:
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