I need help with a piano I'm making for my programming class. Every time I try to compile I get the error
"found int but expected boolean" on my methods with "if" used. Can you guys help me fix this?
Sneaky4296 wrote ...
2012/3/15
Help with abstraction
Here's the code for you guys...
import greenfoot.*; // (World, Actor, GreenfootImage, and Greenfoot)
/**
* A piano that can be played with the computer keyboard.
*
* @author: Jonah Verner
* @version: 0.1
*/
public class Piano extends World
{
/**
* Make the piano.
*/
public Piano()
{
super(800, 340, 1);
makeKeys();
}
public void makeKeys()
{
int i;
int keyWidth;
int keyHeight;
int spaceAtEdge;
int KeyNum = 0;
Key key = new Key(" ", " ");
keyWidth = key.getImage().getWidth();
keyHeight = key.getImage().getHeight();
spaceAtEdge = (800 - keyWidth*12) / 2;
String Note = "";
String Letter = "";
if (KeyNum = 0)
{
Note = "2a#.wav";
Letter = "a";
KeyNum++;
}
if (KeyNum = 1)
{
Note = "2a.wav";
Letter = "s";
KeyNum++;
}
if (KeyNum = 2)
{
Note = "2b.wav";
Letter = "d";
KeyNum++;
}
if (KeyNum = 3)
{
Note = "2c#.wav";
Letter = "f";
KeyNum++;
}
if (KeyNum = 4)
{
Note = "2c.wav";
Letter = "g";
KeyNum++;
}
if (KeyNum = 5)
{
Note = "2d#.wav";
Letter = "h";
KeyNum++;
}
if (KeyNum = 6)
{
Note = "2d.wav";
Letter = "j";
KeyNum++;
}
if (KeyNum = 7)
{
Note = "2e.wav";
Letter = "k";
KeyNum++;
}
if (KeyNum = 8)
{
Note = "2f.wav";
Letter = "l";
KeyNum++;
}
for (i=0; i<12; i++)
{
addObject (new Key (Letter, Note), keyWidth*i + spaceAtEdge + keyWidth/2, keyHeight / 2);
}
}
}
replace if(KeyNum = x) with if(KeyNum == x).
= is used when you're setting something equal to something else (int score = 7 makes a variable "score" and sets it equal to 7.
== is used when you're checking if something is equal to something else (score == 7 checks if the variable "score" is equal to 7, and returns a boolean, meaning that when score is equal to 7, score == 7 is exactly the same as true)
Oh and in case you didn't know (I assume you do but just on the off chance) a boolean is either true or false (just like an int is a whole number)
Finally instead of all those if statements, you could use a switch statement, like so:
I can see something else wrong with your code but I'll post about that later if no-one points it out before me as I have stuff to do right now (Here's a clue: The code setting Note and Letter is outside the for loop).
switch(KeyNum)
{
case 0:
Note = "2a#";
Letter = "a";
break;
case 1:
Note = "2a";
Letter = "s";
break;
case 2:
Note = "2b";
Letter = "d";
break;
//...Etc (fill in the rest)...
case 7:
Note = "2e";
Letter = "k";
break;
case 8:
Note = "2f";
Letter = "l";
}
}
Note += ".wav";You need to login to post a reply.