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Say you have a recursive method, and you post-increment/decrement a value in the recursive call. Why will this result in a stack overflow exception when a pre-increment/decrement will not?

Ex.

numberCount(currentNumber++); //Stack overflow exception

numberCount(++currentNumber); //No stack overflow exception

Thanks in advance for any clarification.

miku
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Derrek Whistle
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2 Answers2

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The first 

numberCount(currentNumber++); //Stack overflow exception

is equivalent to:

numberCount(currentNumber);
currentNumber += 1;

while the the second 

numberCount(++currentNumber); //No stack overflow exception

is equivalent to 

currentNumber += 1;
numberCount(currentNumber);

Need I explain more?

jlordo
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  • I'd add that IMO, this is why you should always use the ++ operator on its own line (except in for loops). That way you don't have to think about this problem. – Daniel Kaplan Apr 19 '13 at 00:19
  • @DerrekWhistle: If the answer was helpful, please don't forget to accept it (checkmark next to it), and maybe even upvote it. – jlordo Apr 19 '13 at 00:21
  • I can't upvote until my rep increases, but i'll gladly accept it. – Derrek Whistle Apr 19 '13 at 00:23
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In case of numberCount(currentNumber++);, if an Exception is thrown by numberCount function, will the variable currentNumber incremented?

Bud Damyanov
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Alagar
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