What shall be the output of the code?
I found this Question in one of the Java Groups on LinkedIn. Wanted to
share with all of you?
public class
JavaMysteryCode {
public static void
main(String args[]) {
Integer a = 100;
Integer b = 100;
Integer c = 5000;
Integer d = 5000;
if (a == b) {
System.out.println("a & b Both are Equal");
}
else {
System.out.println("a & b are Not Equal");
}
if (c == d) {
System.out.println("c & d Both are Equal");
} else {
System.out.println("c & d are Not Equal");
}
}
}
|
Out is as Below:
a & b Both are Equal
c & d are Not Equal // This was not expected right.
|
At first shot I was also shocked and not able to figure out
the Correct output and Why?
Thanks to Gulshan (http://in.linkedin.com/in/gulmathur)
for providing the Answer:
JVM has Pool memory for constants from Integer values -128
to 127, so if you create two or more Integer Ref having value from -128 to 127
then they all are pointing to a same memory area. So a and b both having value
in range of 1 byte they are referring same memory address while c and d contain
value outside this range and memory address for c and d are diff.
