This is the end of Part One, which was hopefully enough to get you started. If you've grasped the main concepts you are good position to attack Part Two, which covers the E language in more detail.
This is probably a good time to look at the different parts of one of the examples from the previous sections, since we've now used quite a bit of E.
The following examination uses the WHILE loop example.
Just to make things easier to follow, each line has been numbered (don't try to compile it with the line numbers on!).
1. PROC main()
2. DEF x,y
3. x:=1
4. y:=2
5. WHILE (x<10) AND (y<10)
6. WriteF('x is \d and y is \d\n', x, y)
7. x:=x+2
8. y:=y+2
9. ENDWHILE
10. ENDPROC
Hopefully, you should be able to recognise all the features listed in the table below. If you don't then you might need to go back over the previous chapters, or find a much better programming guide than this!
Line(s) Observation
---------------------------------------------------------
1-10 The procedure definition.
1 The declaration of the procedure main, with no
parameters.
2 The declaration of local variables x and y.
3, 4 Initialisation of x and y using assignment
statements.
5-9 The WHILE loop.
5 The loop check for the WHILE loop using the
logical operator AND, the comparison operator
`<', and parentheses to group the expression.
6 The call to the (built-in) procedure WriteF
using parameters. Notice the string, the place
holders for numbers, `\d', and the linefeed,
`\n'.
7, 8 Assignments to x and y, adding two to
their values.
9 The marker for the end of the WHILE loop.
10 The marker for the end of the procedure.
Go to the Next or Previous section, the Detailed Contents, or the Amiga E Encyclopedia.