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 ''. In the example below an ampersand can be used to input the empty value.
EXAMPLE
INPUTNULL "&" INPUT @(10,10):Answer,1 IF Answer = '' THEN CRT "A NULL input was received" END
Last update: Sat, 16 Jul 2022 15:34