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mickmackusa ♦
mickmackusa ♦
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Dot operator return different output than what I expected Unexpected evaluation of expression with incrementation, decrementation, multiplication, concatenation, addition-assignment, multiplication-assignment

I've been struggling to understand why this returns 252448 instead of 251248.

<?php $a = 4; echo ++$a * $a++ . $a += $a . $a *= 4; ?>

My thinking is: ++$a * $a++ gives 25 (5*5), after that we have a incremented to 6 and added to itself, so we have 12, and 12 multiplied by 4 so we get 48.

And:

<?php $a = 4; echo ++$a * $a++ . $a *= 4 . $a += $a; ?>

returns 254944 which is even more confusing. I thought that this would return 252448 according to similar logic.

Can anybody explain to me why that is?

Dot operator return different output than what I expected

I've been struggling to understand why this returns 252448 instead of 251248

<?php $a = 4; echo ++$a * $a++ . $a += $a . $a *= 4; ?>

My thinking is: ++$a * $a++ gives 25 (5*5), after that we have a incremented to 6 and added to itself, so we have 12, and 12 multiplied by 4 so we get 48.

And:

<?php $a = 4; echo ++$a * $a++ . $a *= 4 . $a += $a; ?>

returns 254944 which is even more confusing. I thought that this would return 252448 according to similar logic.

Can anybody explain to me why that is?

Unexpected evaluation of expression with incrementation, decrementation, multiplication, concatenation, addition-assignment, multiplication-assignment

I've been struggling to understand why this returns 252448 instead of 251248.

<?php $a = 4; echo ++$a * $a++ . $a += $a . $a *= 4; ?>

My thinking is: ++$a * $a++ gives 25 (5*5), after that we have a incremented to 6 and added to itself, so we have 12, and 12 multiplied by 4 so we get 48.

And:

<?php $a = 4; echo ++$a * $a++ . $a *= 4 . $a += $a; ?>

returns 254944 which is even more confusing. I thought that this would return 252448 according to similar logic.

Can anybody explain to me why that is?

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mickmackusa ♦
mickmackusa ♦
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duplicates list edited from logical vs assignment operator precedence in PHP to Why is $a + ++$a == 2?, PHP operator precedence "Undefined order of evaluation"?, Why does the pre/post increment operator behave wrongly?, PHP - What does "Operator precedence and associativity do not specify an order of evaluation" mean?, logical vs assignment operator precedence in PHP
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mickmackusa ♦
mickmackusa ♦
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Post Closed as "Duplicate" by mickmackusa♦ php
added 9 characters in body
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Abdulla Nilam
Abdulla Nilam
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I've been struggling to understand why this returns 252448252448 instead of 251248251248

<?php $a = 4; echo ++$a * $a++ . $a += $a . $a *= 4; ?>

My thinking is: ++$a * $a++++$a * $a++ gives 25 (5*5), after that we have a incremented to 6 and added to itself, so we have 12, and 12 multiplied by 4 so we get 48.

And:

<?php $a = 4; echo ++$a * $a++ . $a *= 4 . $a += $a; ?>

returns 254944 which is even more confusing. I thought that this would return 252448 according to similar logic. Can

Can anybody explain to me why that is?

I've been struggling to understand why this returns 252448 instead of 251248

<?php $a = 4; echo ++$a * $a++ . $a += $a . $a *= 4; ?>

My thinking is: ++$a * $a++ gives 25 (5*5), after that we have a incremented to 6 and added to itself so we have 12, and 12 multiplied by 4 so we get 48.

And:

<?php $a = 4; echo ++$a * $a++ . $a *= 4 . $a += $a; ?>

returns 254944 which is even more confusing. I thought that this would return 252448 according to similar logic. Can anybody explain to me why that is?

I've been struggling to understand why this returns 252448 instead of 251248

<?php $a = 4; echo ++$a * $a++ . $a += $a . $a *= 4; ?>

My thinking is: ++$a * $a++ gives 25 (5*5), after that we have a incremented to 6 and added to itself, so we have 12, and 12 multiplied by 4 so we get 48.

And:

<?php $a = 4; echo ++$a * $a++ . $a *= 4 . $a += $a; ?>

returns 254944 which is even more confusing. I thought that this would return 252448 according to similar logic.

Can anybody explain to me why that is?

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Sergiusz Strzelczyk
Sergiusz Strzelczyk
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created from staging ground