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Project maintained by Cory Smith

CALL

Transfers control to a BASIC subprogram

Syntax

CALL subprogram_name[( argument_list )]

or

subprogram_name [ argument_list ]`

Notes

subprogram_name is the name of a BASIC subprogram created using a SUB statement.

argument_list is a list of parameters separated by commas. The subprogram can change the values of the parameters.

You can call subprograms with our without the CALL keyword. If you omit CALL, do not place the arguments within parentheses. Also, if you omit CALL, you must use the DECLARE statement. If you omit a declaration, QBasic will supply it automatically.

To prevent a subprogram from changing a parameter’s value, simply place the parameter within parenthesis:

CALL TEST (a, b, (c))

In this case, the subprogram can change the values of the parameters a and b, but not c.

Example

DECLARE SUB SwapVal (a, b)

a = 1
b = 2
CALL SwapVal(a, b)
PRINT a; b
END

SUB SwapVal(x, y)
  temp = x
  x = y
  y = temp
END SUB

Running this program produces the following:

2  1

See Also