Flash MX 2004 Games : Art to ActionScript

Flash MX 2004 Games
Doing things with numbers
Now that you know how to create a variable, let’s use that information to do some simple
arithmetic. No, don’t groan; images and animation will come soon, but for now let’s concentrate
on easy manipulation of simple variables.
1 var x:Number = 10;
2 var y:Number = 7;
3 trace( x + y);
Listing 7.2
The ActionScript in Listing 7.2 will give a result of 17 in the Output window. There are many
operations that you can do using numbers,
Table 7.1 Using symbolic operators with x = 10 and y = 7
Operation Description Example
++ Increment x ++results in 11
−− Decrement x −−results in 9
+ Addition x + y results in 17
− Subtraction x − y results in 3
∗ Multiplication x ∗ y results in 70
/ Division x/y results in 1.42857143
% Modulo, remainder after division x%y results in 3
| Or x|y results in 15
& And x&y results in 2
\ XOR x\y results in 13
≪ Shift left x ≪ y results in 1280
≫ Shift right x ≫ y results in 0
+= Add and assign x+ =y sets x to 17
−= Subtract and assign x− =y sets x to 3
∗= Multiply and assign x∗ =y sets x to 70
/ = Divide and assign x/ = y sets x to 1.42857143
% = Modulo and assign x% = y sets x to 3
|= Or and assign x| =y sets x to 15
& = And and assign x& = y sets x to 2
∧= Xor and assign x∧ =y sets x to 13
≪= Shift left and assign x≪= y sets x to 1280
≫= Shift right and assign x≫= y sets x to 0
Some operators are obvious whereas others need some explanation.
% (modulo) operator
This returns the remainder after division. In this example 10 divided by 7 gives 1 remainder 3 so
the value returned will be 3.
88