INPUTNULL


The INPUTNULL statement allows the definition of a character that will allow a null input to be seen by the INPUT@ statement.

 

COMMAND SYNTAX

INPUTNULL expression

 

SYNTAX ELEMENTS

The expression should evaluate to a single character. Subsequently, any INPUT@ statement that sees only this character input before the new-line sequence will NULL the variable in which input is being stored.

If expression evaluates to the NULL string " then the default character of _ is used to define a NULL input sequence.

 

NOTES

The INPUT statement does not default to accepting the _ character as a NULL input, the programmer must explicitly allow this with the statement:

INPUTNULL "

 

EXAMPLES

INPUTNULL "&"
INPUT @(10,10):Answer,1
IF Answer = " THEN
   CRT "A NULL input was received"
END


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