^= Usage

[Jared Malcolm]

Can anyone explain this to me? Studying for the SCJP and ran across this and couldn't seem to find it used in code.... Anyone mind giving a description and a short code example?

[Ashish Schottky]

@Jared: well it would be better if you gave us an entire question or atleast the reference of it.
From whatever the name of thread suggest, ^ is an ex-or operator.
and a^=b; is equivalent to a=a^b;
So by this way, I think this example might just help you to understand.

a^=b;
b^=a;
a^=b;

The above three lines would swap the numbers in a and b,without using 3rd element.

[Jared Malcolm]

There was no question it was just listed in the book as an assignment operator and I had not seen it used.... So your saying....

a ^= b;

Is the same as....

a = !b;

?

[Ashish Schottky]

@Jared:

There was no question it was just listed in the book as an assignment operator and I had not seen it used.... So your saying....
view plaincopy to clipboardprint?

a ^= b;



Is the same as....

view plaincopy to clipboardprint?

a = !b;



?

No, this is not what I am saying.
Try wikipedia or google for the ex-or operator and its related operations.

! is boolean operator, which will see only true and false values.
^ is ex-or operator which will modify the values.

Consider the two bits a and b , and will list down the truth table for them.

a b a^b
0 0 0
0 1 1
1 0 1
1 1 0
When both bits are 1, the resultant of their exors will be 0.
To learn more about this operator, I will suggest you to write small program which will take in two integers, and print their exor.
say lets assume n=5and m=9;
converitng n in binary gives 101
converting m in binary gives 1001

0 1 0 1
^ 1 0 0 1
------------
1 1 0 0=12 in decimal
so 5^9=12.

so a sample program can be written as

int a=5;
int b=9;
int c=0;
c=a^b;
System.out.println(c);

Which is equivalent to

int a=5;
int b=9;
int b=9;
a^=b;//or b^=a;System.out.println(b);
System.out.println(a);