For checkboxes and multiple select fields, you use it in an array context.
In the next chapter we'll learn how to read and write data files, so you'll be able to save and analyze the data collected by your forms.
cr then ; : intro quote | Welcome to the '24 game'! Using only the - * and / operatorsand all the digits (and only the digits), produce the number '24' Enter your result in 8th syntax, e.g.: 4 4 2 1 * To quit the game, just hit enter by itself. = 0) (expr ) switch *expr case ' ' ; case '-' ; case '*' ; case '/' error "bad syntax" if not x_is_set op = *expr case '1' ; case '2' ; case '3' ; case '4' ; case '5' case '6' ; case '7' ; case '8' ; case '9' error "missing operator" if (x_is_set and op == ' ') error "unavailable digit" unless consume digit expr do operation with (expr - '0') as real case (Cgen "'('") error "missing operator" if (op == ' ' but x_is_set) (new list (new State) (code of del State())) REM Choose four random digits (1-9) with repetitions allowed: DIM digits%(4), check%(4) FOR choice% = 1 TO 4 digits%(choice%) = RND(9) NEXT choice% REM Prompt the player: PRINT "Enter an equation (using all of, and only, the single digits "; FOR index% = 1 TO 4 PRINT ; digits%(index%) ; IF index%4 PRINT " " ; NEXT PRINT ")" PRINT "which evaluates to exactly 24. (setq Result (catch '(NIL) (eval Reply)))) (prinl "-- Evaluation error: " @) ) ((= 24 Result) (prinl " Congratulations!
cr then else cr "You did not use the digits properly, try again." . ; : start \ don't allow anything but the desired words ns:game only intro repeat gen-digits prompt-user get-input check-input again ; start use std, array, list do generate random digits show random digits let result = parse expression (get input line) if result ! (you didn't use all digits)" ; failure else if result == 24.0 print "Correct ! print "Enter an expression that equates to 24 using only all these digits:" printf "%c , %c , %c , %c\n"(digits)(digits)(digits)(digits) printf "24 = " .: some digits are unused :. let stack be a list of State ; class State for (stack = nil) (*expr ! Reply) (prinl "-- Input error: " Reply) ) ((check Expression Numbers Reply) (prinl "-- Illegal Expression") (for S @ (space 3) (prinl S) ) ) ((str?
The program should check then evaluate the expression. When you wish to check your answer enter "=" and it will perform the checks to ensure that you haven't performed any illegal operations, that you have used all four numbers and that your final value is 24. (example: if you are given the digits 2, 2, 6, 9 this program accepts the following solution: 6 * 4 * 2 / 2) The 24 Game Given four digits and using just the , -, *, and / operators; and the possible use of brackets, (), enter an expression that equates to 24. ''' The 24 Game Given any four digits in the range 1 to 9, which may have repetitions, Using just the , -, *, and / operators; and the possible use of brackets, (), show how to make an answer of 24. cashe (remq x cashe))) ;; the parser (define parse (match-lambda ;; parsing arythmetics [`(,x ... " user-expr '= ans)])]))) ;; reading and preparing the user's answer;; "1 2 * (3 4)" --╔═════════════════════════════════════════════════════════════════════════════╗ ║ Argument for the 24 REXX program is either of three forms: (blank) ║ ║ ssss ║ ║ ssss-ffff ║ ║ ║ ║ where SSSS and FFFF must be exactly four numerals (digits) comprised ║ ║ solely of the numerals (digits) 1 ──► 9 (inclusive, with no zeroes). ║ ║ ║ ║ If no argument is specified, the program finds a four digit number (with ║ ║ no zeroes) which has at least one solution, and then displays the number ║ ║ to the user, requesting that they enter a solution in the form of: ║ ║ ║ ║ w operator x operator y operator z ║ ║ ║ ║ where w x y and z are single digit numbers (no zeroes).
The goal is for the player to enter an expression that (numerically) evaluates to 24. Unfortunately, due to the lack of floating-point arithmetic in befunge, divide will result in the answer truncated to an integer. These are your four digits: 9, 2, 8, 7 24 = 9*8/2-7 Wrong! y These are your four digits: 5, 5, 5, 6 24 = 5*5 5-6 Correct! n success:1 failure:1 total:2''' The 24 Game Given any four digits in the range 1 to 9, which may have repetitions, Using just the , -, *, and / operators; and the possible use of brackets, (), show how to make an answer of 24. ║ ║ and operator can be any one of: - * / ║ ║ Parentheses ( ), brackets [ ], and/or braces may be used in the ║ ║ normal manner for grouping expressions. ║ ╚═════════════════════════════════════════════════════════════════════════════╝ A large part of this program deals with validating the user input (and issuing appropriate and meaningful error messages), and also that the digits presented to the user, do in fact, have a possible solution.
The value returned by is always a list, but for text, textarea, password, radio, and single select fields you can use it in a scalar context.Checkboxes allow the viewer to select one or more options on a form.If you assign each checkbox field a different name, you can print them the same way you'd print any form field using Working example: example lets the visitor pick as many options as they want — or none, if they prefer.Since this example uses a different field name for each checkbox, you can test it using Source code: buttons are similar to checkboxes in that you can have several buttons, but the difference is that the viewer can only pick one choice.As with our last checkbox example, the group of related radio buttons must all have the same name, and different values: Source code: usually best to set the values of radio buttons to something meaningful; this allows you to print out the button name and its value, without having to store another list inside your CGI program. Create a new HTML form called colors4.html: Program 5-1: colors4- Favorite Colors HTML Form Working example: create colors4