EXPRESSIONS

Compile Time Step 2: Determine Method Signature

15.11.2

Here the most specific declaration of method

test

 is the one taking a parameter

of type

ColoredPoint

. Because the result type of the method is

int

, a compile 

time error occurs because an

int

 cannot be converted to a

String

 by assignment

conversion. This example shows that, in Java, the result types of methods do not

participate in resolving overloaded methods, so that the second

test

 method,

which returns a

String

, is not chosen, even though it has a result type that would

allow the example program to compile without error.

15.11.2.5

Example: Compile Time Resolution

The most applicable method is chosen at compile time; its descriptor determines

what method is actually executed at run time. If a new method is added to a class,

then Java code that was compiled with the old definition of the class might not use

the new method, even if a recompilation would cause this method to be chosen.

So, for example, consider two compilation units, one for class

Point

:

package points;

public class Point {

public int x, y;

public Point(int x, int y) { this.x = x; this.y = y; }

public String toString() { return toString(""); }

public String toString(String s) {

return "(" + x + "," + y + s + ")";

}

}

and one for class

ColoredPoint

:

package points;

public class ColoredPoint extends Point {

public static final int

RED = 0, GREEN = 1, BLUE = 2;

public static String[] COLORS =

{ "red", "green", "blue" };

public byte color;

public ColoredPoint(int x, int y, int color) {

super(x, y); this.color = (byte)color;

}

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