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Liberty Basic

IrieRom -  
Bonjour,
I would like to learn programming, I bought the book "Learning to Program for Dummies" and it explains how to program with Liberty Basic. At one point, I come across a program that I don’t understand. The topic of this program is "Extracting Characters from a String", I understand the purpose of the given example...

Ex:
FullName$ = "John Barkley Doe"
FirstName$ = LEFT$(FullName$, 4)
PRINT "First Name: "; FirstName$
LastName$ = RIGHT$(FullName$, 3)
PRINT "Last Name: "; LastName$
SecondName$ = MID$(FullName$, 6, 7)
PRINT "Second Name: "; SecondName$
END

... what I don’t understand are the numbers in the parentheses regarding the variables!!!! I really don’t see what the 3, 4, 6, and 7 are for, but they must be important because when we remove them, it doesn’t work anymore...
So if someone can help me, thank you in advance.

6 answers

  1. Anonymous user 
    FullName$ = "John Barkley Doe" FirstName$ = LEFT$( FullName$, 4) PRINT "First Name : "; FirstName$ LastName$ = RIGHT$( FullName$, 3) PRINT "Last Name : "; LastName$ SecondName$ = MID$(FullName$, 6, 7) PRINT "Second Name : "; SecondName$ END


    Hello!
    The first variable is fullName$
    Then, firstName$ is equal to left$(fullName$, 4), which means, left(of the variable, 4), that is, the 4 leftmost characters of your variable...
    PRINT "first name:" firstName$ will display: first name: John
    Then the RIGHT$ function takes as arguments your variable and after the comma the number of characters it takes, from the right, here: Doe.
    Finally, the MID$ function includes 3 arguments: the variable, the start of what you want to extract, and the number of characters you want to extract).

    Like: "we are on ccm" is the variable var$
    left$(var$, 6)= we ar
    right$(var$, 5)= r ccm
    mid$(var$, 3, 6)=e are o

    That's it!

    @+
    0
    1. MadDog
      I don't know, but apparently:
      the syntax of LEFT(string, x)
      should mean that it returns the first x characters
      (so from position 1 to x)
      the syntax of RIGHT(string, y)
      should mean that it returns the last y characters
      (so from position length(string) to length(string)-y)

      and MID(string, x, y)
      returns y characters starting from position x
      (so from position x to x+y)

      Searching for the answer to a question before asking it is
      half the work done. Knowing how to formulate it is an art.
      0
      1. IrieRom
        Well thank you, I appreciate you enlightening me on this point. I can therefore continue my learning. Thanks again, see you next time.
        0
        1. MadDog
          Looking for the answer to a question before asking it is
          half of the work done. Knowing how to formulate it is an art.
          0
          2. wathson

            FullName$ = "John Barkley Doe"
            FirstName$ = LEFT$( FullName$, 4)
            PRINT "First Name: "; FirstName$
            LastName$ = RIGHT$( FullName$, 3)
            PRINT "Last Name: "; LastName$
            SecondName$ = MID$(FullName$, 6, 7)
            PRINT "Second Name: "; SecondName$
            END

            Hello Iron,

            I don't know if anyone has already replied, but I'm doing it anyway

            So the strings associated with FullName$ are very important
            indeed for first name left$ meaning left of the full name and the 4 means the first 4 letters of the full name
            that is "John"

            Likewise for lastName$ 3 characters from the right right$ meaning "Doe"

            concerning the second name, the 6 corresponds to starting from the J of "John" we count 4 characters of "John" + space = 5 characters, so the "B" of "Barkley" starts at the 6th position and counts 7 characters hence (6,7)

            There you go, I hope you understood, I salute you
            0