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Thread: Switch from integer to a float

  1. #1
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    Default Switch from integer to a float

    Hey guys I am trying to get my post-fix expression code to work with a float after I have already created it using an integer, the reason is so that I can get decimal places when I divide. The problem is that I am getting a run time error and I am not sure why. Here is my original code using integers (THAT WORKS) and following is the switch to float. Appreciate any help. Thanks

    import java.util.Stack;
    import java.util.StringTokenizer;
     
    public class P2Evaluate
    {
     
    	private final char ADD = '+';
    	private final char SUBTRACT = '-';
    	private final char MULTIPLY = '*';
    	private final char DIVIDE = '/';
     
    	Stack<Integer> stack = new Stack<Integer>();
     
    	public int evaluate (String expr)
    	{
    		int op1 = 0;
    		int op2 = 0;
    		int result = 0;
    		String token;
    		StringTokenizer tokenizer = new StringTokenizer(expr);
     
    		while (tokenizer.hasMoreTokens())
    		{
    			token = tokenizer.nextToken();
     
    			if (isOperator(token))
    			{
    				op2 = (stack.pop()).intValue();
    				op1 = (stack.pop()).intValue();
    				result = evalSingleOp (token.charAt(0), op1, op2);
    				stack.push (new Integer(result));
    			}
    			else
    			{
    				stack.push (new Integer(Integer.parseInt(token)));
    			}
     
     
    		}
           return result;
    	}
     
    	private boolean isOperator (String token)
    	{
    		return (token.equals("+") || token.equals("-") || token.equals("*") || token.equals("/"));
    	}
     
    	private int evalSingleOp (char operation, int op1, int op2)
    	{
    		int result = 0;
     
    		switch (operation)
    		{
    			case ADD:
    				result = op1+op2;
    				break;
    			case SUBTRACT:
    				result = op1-op2;
    				break;
    			case MULTIPLY:
    				result = op1*op2;
    				break;
    			case DIVIDE:
    				result = op1/op2;
    		}
    		return result;
    	}
     
    }
     
    import java.util.Stack;
    import java.util.StringTokenizer;
     
     
    public class P2Evaluate
    {
     
    	private final char ADD = '+';
    	private final char SUBTRACT = '-';
    	private final char MULTIPLY = '*';
    	private final char DIVIDE = '/';
     
    	Stack<Float> stack = new Stack<Float>();
     
    	public float evaluate (String expr)
    	{
    		float op1 = 0;
    		float op2 = 0;
    		float result = 0;
    		String token;
    		StringTokenizer tokenizer = new StringTokenizer(expr);
     
    		while (tokenizer.hasMoreTokens())
    		{
    			token = tokenizer.nextToken();
     
    			if (isOperator(token))
    			{
    				op2 = (stack.pop()).floatValue();
    				op1 = (stack.pop()).floatValue();
    				result = evalSingleOp (token.charAt(0), op1, op2);
    				stack.push (new Float(result));
    			}
    			else
    			{
    				stack.push (new Float(Float.valueOf(token).floatValue()));
    			}
     
     
    		}
           return result;
    	}
     
    	private boolean isOperator (String token)
    	{
    		return (token.equals("+") || token.equals("-") || token.equals("*") || token.equals("/"));
    	}
     
    	private float evalSingleOp (char operation, float op1, float op2)
    	{
    		float result = 0;
     
    		switch (operation)
    		{
    			case ADD:
    				result = op1+op2;
    				break;
    			case SUBTRACT:
    				result = op1-op2;
    				break;
    			case MULTIPLY:
    				result = op1*op2;
    				break;
    			case DIVIDE:
    				result = op1/op2;
    		}
    		return result;
    	}
     
    }
    Exception in thread "AWT-EventQueue-0" java.lang.NoSuchMethodError: P2Evaluate.e
    valuate(Ljava/lang/String;)I
            at P2Control$solveListener.actionPerformed(P2Control.java:55)
            at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:20
    18)
            at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.jav
    a:2341)
            at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel
    .java:402)
            at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259
    )
            at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonL
    istener.java:252)
            at java.awt.Component.processMouseEvent(Component.java:6504)
            at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
            at java.awt.Component.processEvent(Component.java:6269)
            at java.awt.Container.processEvent(Container.java:2229)
            at java.awt.Component.dispatchEventImpl(Component.java:4860)
            at java.awt.Container.dispatchEventImpl(Container.java:2287)
            at java.awt.Component.dispatchEvent(Component.java:4686)
            at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832
    )
            at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
     
            at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
            at java.awt.Container.dispatchEventImpl(Container.java:2273)
            at java.awt.Window.dispatchEventImpl(Window.java:2713)
            at java.awt.Component.dispatchEvent(Component.java:4686)
            at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
            at java.awt.EventQueue.access$000(EventQueue.java:101)
            at java.awt.EventQueue$3.run(EventQueue.java:666)
            at java.awt.EventQueue$3.run(EventQueue.java:664)
            at java.security.AccessController.doPrivileged(Native Method)
            at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDo
    main.java:76)
            at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDo
    main.java:87)
            at java.awt.EventQueue$4.run(EventQueue.java:680)
            at java.awt.EventQueue$4.run(EventQueue.java:678)
            at java.security.AccessController.doPrivileged(Native Method)
            at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDo
    main.java:76)
            at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
            at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThre
    ad.java:211)
            at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.
    java:128)
            at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThre
    ad.java:117)
            at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
     
            at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
     
            at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Switch from integer to a float

    I am getting a run time error
    Please copy the full text of the error message and paste it here.

    Please edit your post and wrap your code with
    [code=java]
    <YOUR CODE HERE>
    [/code]
    to get highlighting and preserve formatting.
    If you don't understand my answer, don't ignore it, ask a question.

  3. #3
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    Default Re: Switch from integer to a float

    Quote Originally Posted by Norm View Post
    Please copy the full text of the error message and paste it here.

    Please edit your post and wrap your code with
    [code=java]
    <YOUR CODE HERE>
    [/code]
    to get highlighting and preserve formatting.
    I corrected the formatting

  4. #4
    Super Moderator Norm's Avatar
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    Default Re: Switch from integer to a float

    java.lang.NoSuchMethodError: P2Evaluate.evaluate(Ljava/lang/StringI
    at P2Control$solveListener.actionPerformed(P2Control. java:55)
    That type of error normally happens at compile time. It looks like a class was changed after another class was compiled using the earlier version.

    Try recompiling all the classes and test again.
    If you don't understand my answer, don't ignore it, ask a question.

  5. #5
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    Default Re: Switch from integer to a float

    That did the trick. Thanks.

  6. #6
    Member Zyrion's Avatar
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    Default Re: Switch from integer to a float

    Never mind. I see your issue is resolved.

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