具有双值的 Java MethodOverloading 错误

Question

这是我遇到问题的部分代码:

===类重载===

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(); }

它编译没有错误，但是当我尝试运行它时，输出是:

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

我做错了什么？

我在 Ubuntu 10.10、Netbeans 6.9 上。

谢谢。

Answer 1

double 值的格式说明符是 f，而不是 d。所以这一行应该是:

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

有关格式说明符的更多详细信息 here .