NUM(), NUMS()

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The NUM() function tests whether a string can be converted to a number. The NUMS() function is similar to NUM() but operates on successive elements of a dynamic array, returning a similarly structured dynamic array of results.

 

 

Format

 

NUM(string)

 

where

 

stringevaluates to the string to be tested.

 

 

The NUM() function returns true (1) if the string can be converted to a number. The function returns false (0) for a string which cannot be converted to a number. A null string is a valid representation of zero and hence causes NUM() to return true.

 

 

Example

 

LOOP

  DISPLAY "Enter part number ":

  INPUT PART.NO

UNTIL LEN(PART.NO) AND NUM(PART.NO)

  PRINTERR "Part number is invalid"

REPEAT

 

This program fragment prompts for and inputs a part number. If the data entered is null or cannot be converted to a number, an error message is displayed and the prompt is repeated.