int a = 3;
int b = (a=2)*a;
int c = b * (b=5);
System.out.println("a=" + a + " b=" + b + " c=" + c);
Can someone explain me why the output is:
a=2 b=5 c=20
instead of
a=2 b=4 c=20
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4 Answers
Because assignment is an operator which returns the new value it set and, while it's normally last in precedence, the parentheses move it up before the non-parenthetical operators. Think of it like this:
ais set to 3.ais set to 2, returning 2. That is then multiplied by the new value ofa, which is 2, settingbto 4.- 4 (old
b) is multiplied by the result ofb=5, which is 5.bis now 5, andcis set to the4x5value (20).
Comments
You have reassigned b to a 5 in the second statement. As a result b will be 5 until it is assigned again. What part of this is confusing you?
1 Comment
jojuk
Oh now I get it. I forgot about the second assignment. Such a stupid question I've asked..
You are assigning 5 to b, in the third line. So, that's what it contains.
2 Comments
ford prefect
@Cruncher I don't think it's assignment as comparison just a misunderstanding of scope
Cruncher
@inquisitiveIdiot Oh, I didn't even look that close. I just saw
b=5 inside of an expression and sort of assumedb is 5 because of this (b=5);
a is 2 because of this (a=2)
c is 20 because of this 4 * (b=5);
answered Nov 11, 2013 at 15:47
Prabhakaran Ramaswamy
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