FYI about wrapping 32-bit integers

Question

This is a note for newbies, however, I have a question that came up writing this post that I'd appreciate any experts addressing. Please see the bottom of the post, "Code" Question.
I am not talking about wrapping a class around a primitive. I am talking about the low level issue of what happens internally to a 32-bit integer value as the bits wrap around either limit of the data type.
This is a FYI for noobs like me! Consider the following code:long bigValue = 53*52*51*50*49*48;
System.out.println(bigValue);Looks ok to us noobs, right? But the output this produces is -650,483,584 (I added the commas). When I did this I was puzzled for a bit, then I remembered that when you add to a value an amount that exceeds the upper limit of that type (subtract past the lower limit) the value can wrap. For example, a Java byte - an 8-bit type - has a range of -128 to 127. If I have a variable of type byte equal to 127 and add 1 to it, the result is -128! The bits inside wrapped around.
In my code sample, what is salient is that in Java an integer literal is always assumed to be an int - a 32-bit integer - which has a range of:-
-2,147,483,648 to 2,147,483,647. The resulting multiplication I was doing equals 16,529,000,000 which is out of range for an int, so it wrapped and gave me the negative value.
It didn't matter that bigValue was of type long. Java was looking first at the operations which contains integer literals; therefore it internally used an int to perform the multiplication, which caused the bit-wrapping. Fortunately, you can force Java to use a long value all the way through this computation by forcing the first literal to represent a long (a 64-bit value). Example:
long bigValue = 53L*52*51*50*49*48;
System.out.println(bigValue);
Notice the capital "L" after "53". That forced Java to read "53" as a long, and thereafter it continued to perform the multiplication steps on a long instead of an int, finally yielding the correct value to assign to bigValue.
...Just thought other newbies would appreciate the heads-up.
"Code" Question
When trying to write the second code snippet, the part "53L" would look like "53" in the preview. I could not figure out how to "escape" the "L" so it would show up. Anyone know how to do that?

Answer 1

kajbj and vanilla_lorax...
Thanks for the explanation and "fix".
Have y'all had trouble with the B,
I,
U, and code buttons? Every time I
click on them I get an "Error on page" in the leftof
my browser's status bar....Try clearing your browser's cached files. It might
help.Nope, didn't help.