TTEFP (floatvar, floatstr$)


QView Tiny Toolkit

This function tries to convert the string given as the second parameter into a floating point number and assign this value to the floating point variable given as the first argument. There is no difference to the assignment:

floatvar = floatstr$

except where an error occurs, ie. if floatstr$ cannot be converted to a float. Whereas the assignment above will break with an error, TTEFP will allow you to track that down by checking its return; the number returned by TTEFP is the QDOS error code (or 0 if the assignment was successful).


A piece of code which asks for the age of the user would look similar to this:

100 CLS
110 REPeat question
120   INPUT "How old are you?"!age$
130   ec = TTEFP(age, age$)
140   SELect ON ec
150     = 0: IF age < 13 OR age > 100 THEN
160            PRINT "You're surely kidding!!"
170          ELSE EXIT question
180          END IF
190     = -17: PRINT "Digits, not letters, ok?"
200     = -18: PRINT "Reasonable numbers, please."
210     = REMAINDER : PRINT "What's this about?"
220   END SELect
230 END REPeat question
240 PRINT "So you are"!age!"years old... :-)"