I want to share 1 question which is asked most of the time in interviews and I wasn't able to e answer that question, but finally I found the answer:
How to Swap 2 variable value without using 3rd variable??
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1@ShankarDamodaran Oops sorry, i am not aware of it, i thought it was not in StackOverflow, that's why i have shared it! – Jay Aug 21 '13 at 11:51
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No problem. Glad you got the solution. – Shankar Narayana Damodaran Aug 21 '13 at 11:52
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I also had that kind of interview, they are very stupid IMO, how can they judge how good you are in your area with such trivial things? – itsjavi May 18 '17 at 11:56
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try my solution : https://stackoverflow.com/questions/3541730/is-there-a-php-function-for-swapping-the-values-of-two-variables/72650266#72650266 – pankaj Jun 16 '22 at 18:24
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This method will work for any variable type:
$a = 5;
$b = 6;
list($a, $b) = array($b, $a);
print $a . ',' . $b;
Output:
6,5
Another simple way (which only works for numbers, not strings/arrays/etc) is
$a = $a + $b; // 5 + 6 = 11
$b = $a - $b; // 11 - 6 = 5
$a = $a - $b; // 11 - 5 = 6
print $a . ',' . $b;
Output:
6,5
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@mjolnic does variables and objects are different or same? , here is question is about variables but not objects. – Chintan Gor May 23 '17 at 13:12
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Surely you want the XOR swap algorithm ? At least for numeric variables.
Conventional swapping requires the use of a temporary storage variable. Using the XOR swap algorithm, however, no temporary storage is needed. The algorithm is as follows:
X := X XOR Y
Y := X XOR Y
X := X XOR Y
Although I've never seen it used in real scenarios (beyond assembler work)
Brian Agnew
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it's too difficult to implement, as we want simpler approach for simple operation, like variable swapping. – Raptor Aug 21 '13 at 11:44
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