QBASIC TUTORIAL 3 - Strings

Strings

There are certain types of data (or information) called "strings." Strings contain a sequence of characters (letters, numbers, and symbols) enclosed in quotation marks. For example, "Hello World!" is a string.

With the PRINT command, you can also print numbers to the screen. Delete the current program (unless you already have) and write the following:

        PRINT 512 (or ?512)

<press Enter>

Press F5 to run the program. The program outputs:

        512

NOTE: Always remember to put CLS before running another program.

Expressions

An expression is something the interpreter calculates (or evaluates). Such as:

        1 + 1 (returns 2)

        100 - 47 (returns 53)

        3 * 34 (returns 102)

        80 / 4 (returns 20)

        (100 * 3) + 56 (returns 356)

Output:

NOTE: The asterisk (*) means to multiply two numbers; the slash (/) means to divide.

If you pass an expression to the PRINT command, the value returned (a number) is printed.

Clear the current program, and then run the following:

         PRINT 512 + 478

Program output:

         990

If you enclose the expression with quotation marks, the expression becomes a string and isn't evaluated. For example:

          PRINT "512 + 478"

Output:

           512 + 478

More about the PRINT command

You can use multiple print statements in your program.

          PRINT "Hello"

          PRINT "World"

Output:

         Hello

         World

To place World onto the previous line, place a semi-colon after PRINT "Hello".

         PRINT "Hello";

         PRINT "World"

Output:

         HelloWorld

Also, if you put a space before the strings on the first line, the program will insert spaces between the two words.

         PRINT "Hello ";

         PRINT "World"

Output:

         Hello World

What you learned in Tutorial 3
1. Strings
2. Expression 
3. Print (continuation)

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