variable assignment inside if-expression?

[autocart]

Hi,

This code

Code: Select all

if ($v = 1) {echo $v;}
  else {echo "else";}

echos "$v".

This code

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$v = 0;
  if ($v = 1) {echo $v;}
  else {echo "else";}

echos "0".

This code

Code: Select all

$v = 0;
  if ($v) {echo $v;}
  else {echo "else";}

echos "else".

I only understand the third one. How does XY handle assignments inside the if expression? (There is no error message.)
Thx.

[admin]

That's not supported.

Tip: Tick "Scripting | Syntax Checking" and you would have been told.

[autocart]

ok, thx for the info

[PeterH]

OK: 2 * autocart, 1 * Don

1) comparison isn't = but ==
2) first example with == would test an uninitialized variable: dangerous!
3) @Don: is it ideal that neither a decimal nor a boolean comparison to an uninitialized var resolves to true, but all to false? While ($v = '$v') is true?
So maybe an uninitialized var *could* be treated as 0 or false. Question: what does meet more expectations

[admin]

Difficult question, but changing this now could break old code, so let's just leave it as it is.

[PeterH]

Difficult question, but changing this now could break old code, so let's just leave it as it is.

Thanks. No problem. Just wanted to ask

[autocart]

OK: 2 * autocart, 1 * Don

1) comparison isn't = but ==
2) first example with == would test an uninitialized variable: dangerous!
3) @Don: is it ideal that neither a decimal nor a boolean comparison to an uninitialized var resolves to true, but all to false? While ($v = '$v') is true?
So maybe an uninitialized var *could* be treated as 0 or false. Question: what does meet more expectations

Hi, thx for the input.
Still, for clarification, when I wrote "=" I did mean "=". I was not trying to make a comparision at all but as the title says. I think Don understood me correctly and it is not supported.