5.2

Assignment Conversion

CONVERSIONS AND PROMOTIONS

char c =  \u0123 ;

long l = c;

//

widen

char

 to

long

System.out.println("l=0x" + Long.toString(l,16));

f = 1.23f;

double d = f;

//

widen

float

 to

double

System.out.println("d=" + d);

}

}

It produces the following output:

f=12.0

i=0x123

d=1.2300000190734863

The following test, however, produces compile time errors:

class Test {

public static void main(String[] args) {

short s = 123;

char c = s;

//

error: would require cast

s = c;

//

error: would require cast

}

}

because not all

short

 values are

char

 values, and neither are all

char

 values

short

 values.

A value of reference type must not be assigned to a variable of primitive type;

an attempt to do so will result in a compile time error.

A value of the null type (the null reference is the only such value) may be

assigned to any reference type, resulting in a null reference of that type.

Here is a sample program illustrating assignments of references:

public class Point { int x, y; }

public class Point3D extends Point { int z; }

public interface Colorable {

void setColor(int color);

}

public class ColoredPoint extends Point implements Colorable

{

int color;

public void setColor(int color) { this.color = color; }

}

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