When i attempt to run this code it keeps returning the wrong value and i can not figure out where i went wrong. It prints out correctly after I add 10 to catUp but when I check to see if that same value is greater then 199 it falls through that if statement for some reason. Also when I print it out at the end of the upCategory method it gives the value 1, but when I go to print it out in the main it gives me a value of 3.
public void upCategory()
{
double catUp = radioXM.getCurrentStaion();
catUp += 10;
System.out.println(catUp);
if (catUp > 199.0);
{
catUp = 1;
radioXM.setCurrentStation(catUp);
System.out.println(catUp);
}
radioXM.setCurrentStation(catUp);
System.out.println(catUp);
}
public static void main (String [] args) {
AutoRadioSystem c = new AutoRadioSystem();
c.selectRadio();
double b = c.getCurrentStation();
System.out.println(b);
// this changes the radio to XM
c.selectRadio();
double d = c.getCurrentStation();
System.out.println(d);
//this is suppose to change the station up by 10 but gives incorrect value
c.upCategory();
double f = c.getCurrentStation();
System.out.println(f);
}
Additional code that goes with it...
public abstract class Radio
{
double currentStation;
RadioSelectionBar radioSelectionBar;
public Radio()
{
this.currentStation = getMin_Station();
}
public abstract double getMax_Station();
public abstract double getMin_Station();
public abstract double getIncrement();
public void up()
{
}
public void down()
{
}
public double getCurrentStaion()
{
return this.currentStation;
}
public void setCurrentStation(double freq)
{
currentStation += freq;
}
public void setStation(int buttonNumber, double station)
{
}
public double getStation(int buttonNumber)
{
return 0.0;
}
public String toString()
{
String message = ("" + currentStation);
return message;
}
public boolean equals (Object o)
{
if (o == null)
return false;
if (! (o instanceof Radio))
return false;
Radio other = (Radio) o;
return this.currentStation == other.currentStation;
}
public class XMRadio extends Radio
{
private static final double Max_Station = 199;
private static final double Min_Station = 1;
private static final double Increment = 1;
public XMRadio()
{
}
public double getMax_Station()
{
return this.Max_Station;
}
public double getMin_Station()
{
return this.Min_Station;
}
public double getIncrement()
{
return this.Increment;
}
public String toString()
{
String message = ("XM "+ currentStation );
return message;
}
}
This line is the problem:
if (catUp > 199.0);
Java treats the semicolon as the body for the if
statement, and the block in braces below the if
becomes a normal block, and is always executed.
To attach the block in braces to the if
statement, remove the semicolon:
if (catUp > 199.0)
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