Turing/Functions and Subroutines

Functions

I never use these, so I can't really say anything useful about them, except that they are used to make calculations that you often use. Let's say you want to make a program that gets radii and outputs the area of the circle.

function calculatearea (x : real) : real
    result x ** 2 * 3.14159
end calculatearea
var input : real
loop
    get input
    put "The area of a circle with a radius ", input, " is ", calculatearea (input)
end loop

Procedures

These are great for things that you do often or just to make your program look more organized. Let's say that you want to get the keyboard input, then the mouse input, then the keyboard input and then output both, get the mouse input and then output both. Instead of copying and pasting bits of code, you can have procedures and call them when needed.

 var mx,my,mb : int
 var keyinput : string
 procedure getmouse
    Mouse.Where (mx,my,mb)
 end getmouse
 procedure getkey
    get keyinput
 end getkey
 procedure outputinfo
    put mx, my, mb
    put keyinput
 end outputinfo
 loop
   keyinput
   getmouse
   outputinfo
   getmouse
   outputinfo
 end loop

Exercises:

1. Make a function that calculates the number times 6, plus 3 divided by 2
2. Make a procedure that puts 'hi' and then one that gets a string. Then call on them at random. (Hint: Use Rand.Int: Rand.Int (1,5) randomly outputs a number between 1 and 5.)

Project: Turing

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