Java MethodOverloading error with double values

问题

Here is a part of my code I'm having trouble with:

===Class Overload===

public class Overload  
{    
    public void testOverLoadeds()  
      {  
        System.out.printf("Square of integer 7 is %d\n",square(7));  
        System.out.printf("Square of double 7.5 is %d\n",square(7.5));  
    }//..end testOverloadeds  

    public int square(int intValue)
    {


 System.out. printf("\nCalled square with int argument: %d\n",intValue);
   return intValue * intValue;
}//..end square int

public double square(double doubleValue)
        {
System.out.printf("\nCalled square with double argument: %d\n", doubleValue);
return doubleValue * doubleValue;

}//..end square double
}//..end class overload


 ===Main===
public static void main(String[] args) {

    Overload methodOverload = new Overload();
    methodOverload.testOverLoadeds(); }

It compiles with no error, however when I try to run it the output is:

Called square with int argument: 7
Square of integer 7 is 49

Exception in thread "main" java.util.IllegalFormatConversionException: d != java.lang.Double at java.util.Formatter$FormatSpecifier.failConversion(Formatter.java:3999) at java.util.Formatter$FormatSpecifier.printInteger(Formatter.java:2709) at java.util.Formatter$FormatSpecifier.print(Formatter.java:2661) at java.util.Formatter.format(Formatter.java:2433) at java.io.PrintStream.format(PrintStream.java:920) at java.io.PrintStream.printf(PrintStream.java:821) at methodoverload.Overload.square(Overload.java:19) at methodoverload.Overload.testOverLoadeds(Overload.java:8) at methodoverload.Main.main(Main.java:9) Called square with double argument:Java Result: 1

What am I doing wrong?

I'm on Ubuntu 10.10, Netbeans 6.9.

Thanks.

回答1:

The format specifier for double values is f, not d. So this line should be:

 System.out.printf("\nCalled square with double argument: %f\n", doubleValue);

More details about the format specifiers here.

回答2:

try this

   public class Overload {
    public void testOverLoadeds() {
        System.out.printf("Square of integer 7 is %d\n", square(7));
        System.out.printf("Square of double 7.5 is %.4f%n", square(7.5));
    }// ..end testOverloadeds

    public int square(int intValue) {
        System.out.printf("\nCalled square with int argument: %d\n", intValue);
        return intValue * intValue;
    }// ..end square int

    public double square(double doubleValue) {
        System.out.printf("\nCalled square with double argument: %.4f%n",doubleValue);
        return doubleValue * doubleValue;

    }// ..end square double
    // ..end class overload

    public static void main(String[] args) {

        Overload methodOverload = new Overload();
        methodOverload.testOverLoadeds();

    }
}

You need to change the double formatter "%d\n"

来源：https://stackoverflow.com/questions/4568345/java-methodoverloading-error-with-double-values

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