Overloaded method return type

[Shiva Mohan]

int go(byte i){//overloaded method
System.out.println(i);
return i;
}

System.out.println(myObject.go((byte)128));

Here,byte maximum range is 127.i thought it would display error.how come it takes -128 value.Can anyone please explain the rule for me.

[Keith Lynn]

Originally posted by Shiva Mohan:
int go(byte i){//overloaded method
System.out.println(i);
return i;
}

System.out.println(myObject.go((byte)128));

Here,byte maximum range is 127.i thought it would display error.how come it takes -128 value.Can anyone please explain the rule for me.

You are casting 128 to a byte before you send it to the method.

[Shiva Mohan]

128 byte value is 1000 0000.How come -128.Still don't understand......

[Karol Kisielewski]

Originally posted by Shiva Mohan:
int go(byte i){//overloaded method
System.out.println(i);
return i;
}

System.out.println(myObject.go((byte)128));

Here,byte maximum range is 127.i thought it would display error.how come it takes -128 value.Can anyone please explain the rule for me.

There is nothing strange with this. The int literal (which is 32 bits long) is explicite casting to byte (8 bit):
128 = 00000000 00000000 00000000 10000000
casting to byte truncate 24 highest bits and gives:
10000000=-128

Compiler allows for this bacause it trust you and know that you know what you are doing

[Keith Lynn]

128 is an int literal. Its bit representation is

00000000 00000000 00000000 10000000

When it's cast to a byte, its bit representation is

10000000

This is a negative number because the sign bit is 1.

To find out what negative number it is, flip the bits and add 1.

01111111
00000001

10000000

So the number is -128.

[Shiva Mohan]

Thankyou very much karol and keith.