Here's our second program.
Before typing it in, click the new program button on the toolbar , to tell Basic4GL we
are working on a new and different program.
print "4 + 5 = " print 4 + 5 |
Again, click on the "Go" button to run the program.
So now we can use Basic4GL as a calculator!
Infact we've just written our first expression!
You've just written your first expression: 4
+ 5
And the computer has calculated the result and displayed it (with
print).
Again let's break it down.
This program has two instructions. Each on a different line.
print "4 + 5 = "
This is just like the Hello World program. We have used the print
command, and supplied it with the text "4 + 5 =
" as a quoted string. We know that this means write
the text "4 + 5 =" to the screen.
print 4 + 5
This looks much like the first line, except the 4 + 5 is
not a quoted string anymore. We are using the print
command again, but this time using 4 + 5 as the
parameter.
So what does the computer do? It evaluates 4
+ 5 first. It calculates that 4 + 5 equals 9, and then
sends 9 through to print as the parameter.
So the second line prints out a 9 on the screen.
Try modifying the program to calculate other equations. Here are some examples:
4 + 5 + 6 | |
7 * 8 | * means multiplication |
14.2 - .5 | |
3 / 2 | / means division |
1 + 2 * 3 | |
(1 + 2) * 3 | |
sqrt (2) | |
(1 + sqrt (2)) * 2 | |
"Cat" + "fish" | |
"Five" + 5 | |
"1" + "3" | |
"4 x 5 = " + 4 * 5 |
Some notes to be aware of: