Demo Programs

In this chapter we will see simple demo programs

• Language Shell
• Main Menu

Language Shell

We can create simple interactive programming environment using the next program

while true
        see nl + "code:> "
        give cCode
        try
                eval(cCode)
        catch
                see cCatchError
        done
end

Output:

code:> see "hello world"
hello world
code:> for x = 1 to 10 see x + nl next
1
2
3
4
5
6
7
8
9
10

code:> func test see "Hello from test" + nl

code:> test()
Hello from test

code:> bye

Main Menu

Example:

# Demo Program

while true

        see "

        Main Menu
        ===========
        [1] Say Hello
        [2] Sum two numbers
        [3] Stars
        [4] Fact
        [5] Exit

        " give nMenu see nl

        # we can use Switch-ON-Other-OFF instead of IF-BUT-ELSE-OK

        if nMenu = 1 sayhello()
        but nMenu = 2 Sum()
        but nMenu = 3 Stars()
        but nMenu = 4
                see "Enter Number : " give x
                see "Output : "

                Try
                        see Fact(number(x))
                Catch
                        see "Error in parameters!" + nl
                Done

        but nMenu = "5" return
        else see "bad option" + nl
        ok

end

func sayhello
        see "Enter your name ? " give fname
        see "Hello " + fname + nl

func sum
        see "number 1 : " give num1 see "number 2 : " give num2
        see "Sum : " see 0 + num1 + num2

func stars
        for x = 1 to 10
                see space(8)
                for y = 1 to x see "*" next see nl
        next

func fact x if x = 1 return 1 else return x * fact(x-1) ok

func space x y = "" for t=1 to x y += " " next return y

Output:

        Main Menu
        ===========
        [1] Say Hello
        [2] Sum two numbers
        [3] Stars
        [4] Fact
        [5] Exit

        1

Enter your name ? Mahmoud Fayed
Hello Mahmoud Fayed


        Main Menu
        ===========
        [1] Say Hello
        [2] Sum two numbers
        [3] Stars
        [4] Fact
        [5] Exit

        2

number 1 : 3
number 2 : 4
Sum : 7

        Main Menu
        ===========
        [1] Say Hello
        [2] Sum two numbers
        [3] Stars
        [4] Fact
        [5] Exit

        3

        *
        **
        ***
        ****
        *****
        ******
        *******
        ********
        *********
        **********


        Main Menu
        ===========
        [1] Say Hello
        [2] Sum two numbers
        [3] Stars
        [4] Fact
        [5] Exit

        4

Enter Number : 5
Output : 120

        Main Menu
        ===========
        [1] Say Hello
        [2] Sum two numbers
        [3] Stars
        [4] Fact
        [5] Exit

        5