The Demons Command Each Other
From Huben's Wiki
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| + | This needs to be extended to explain the idea of execution flow during a call, especially the idea of returning to where you were called. Then the test can also be extended. | ||
| + | Have some code they can run, explaining how to step through a program in Dr. Java. | ||
| + | --> | ||
| + | [[Image:Gort.jpeg]] | ||
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We have penetrated the mysteries of finding demon commands. Now we must seek to use those commands, and thus control our demons. | We have penetrated the mysteries of finding demon commands. Now we must seek to use those commands, and thus control our demons. | ||
==(A) First Call== | ==(A) First Call== | ||
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public class Nietzsche | public class Nietzsche | ||
{ | { | ||
| − | public void speak() | + | static public void speak() |
{ | { | ||
System.out.println("Thus spake Zarathustra!"); | System.out.println("Thus spake Zarathustra!"); | ||
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* The third line of main() shows another way to invoke the speak() of DayTheEarthStoodStill. Why does this work? | * The third line of main() shows another way to invoke the speak() of DayTheEarthStoodStill. Why does this work? | ||
* What rule would you make to explain why sometimes you can call with just the name of a method and other times you need something more complex? | * What rule would you make to explain why sometimes you can call with just the name of a method and other times you need something more complex? | ||
| + | * If you are looking at Nietzsche and hit run, for once the error message makes sense. Why does this give an error? | ||
==(C) Method Calls In Real Programs== | ==(C) Method Calls In Real Programs== | ||
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* How many arguments does setBounds() have? | * How many arguments does setBounds() have? | ||
* Do these 3 last method calls return any values? | * Do these 3 last method calls return any values? | ||
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| + | ==(D) Do you get it?== | ||
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| + | Look at studentdisk/Ch07/Craps/RollingDie.java. | ||
| + | * List the methods of class RollingDie. | ||
| + | * How many arguments does each of those methods need? | ||
| + | * Where are each of those methods called in class RollingDie (0 to many places.) | ||
| + | * What is the name of the constructor method? Is there a coincidence involved? | ||
| + | * How many different methods of class Math are called? | ||
All you need now are variables, objects, arguments and conditionals: then you shall understand most of the wiles of these demons in Java code. | All you need now are variables, objects, arguments and conditionals: then you shall understand most of the wiles of these demons in Java code. | ||
