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How to clone a string?

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Join Date: Oct 2006

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edek

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How to clone a string?

Nov 9th, 2008

I have a reference to some string. I need to copy (clone) that string.
This is what I tried

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 PHP Syntax (Toggle Plain Text) 
$newString = $refToString; //this just copies the ref - no new memory allocated
$newString = clone $refToString; //this creates "__clone method called on non-object" error
$newString = $refToString; //this just copies the ref - no new memory allocated
$newString = clone $refToString; //this creates "__clone method called on non-object" error

If anyone knows how to do this, please help!
Thanks

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Join Date: Sep 2005

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digital-ether digital-ether is offline

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Re: How to clone a string?

Nov 9th, 2008

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Originally Posted by edek

I have a reference to some string. I need to copy (clone) that string.
This is what I tried
Help with Code Tags

PHP Syntax (Toggle Plain Text)
$newString = $refToString; //this just copies the ref - no new memory allocated
$newString = clone $refToString; //this creates "__clone method called on non-object" error
$newString = $refToString; //this just copies the ref - no new memory allocated $newString = clone $refToString; //this creates "__clone method called on non-object" error
If anyone knows how to do this, please help!
Thanks

I believe strings are always copied/cloned on either assignment or modification.

Try:

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 php Syntax (Toggle Plain Text) 
$str = "joe";
$str2 = $str;  
$str2 .= " blo"; // you have cloned $str to $str2 by modifying $str2
 
echo $str; // would give you: joe
$str = "joe";
$str2 = $str;  
$str2 .= " blo"; // you have cloned $str to $str2 by modifying $str2

echo $str; // would give you: joe

I'm sure this holds for all PHP versions to date since strings are "basic" types.

Objects are referenced however in PHP5 and above. PHP4 Objects are referenced on assignment. But cloned on modification.

Last edited by digital-ether; Nov 9th, 2008 at 9:29 pm.

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Join Date: Oct 2006

Posts: 113

Reputation: edek is an unknown quantity at this point

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edek

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Re: How to clone a string?

Nov 10th, 2008

Yes, it works like it should. I just left it for a while, and when I got back It just worked like it should. I'm also unable to reproduce the problem.
\Thanks for your reply anyway!

Last edited by edek; Nov 10th, 2008 at 8:31 am.

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martin5211 martin5211 is offline

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Re: How to clone a string?

Nov 10th, 2008

I think clone is only used to clone object references on PHP 5. For some reason $refToString contained a string or null value result, that's why PHP indicated that error.