I want to do define the following variable $url
$url = www.example.com/$link;
where $link is another predefined variable text string e.g. testpage.php
But the above doesn't work, how do I correct the syntax?
Thanks
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Did we all posted at the same time? I swear when I saw this question there was no answer and now there are 5 lolAntonioCS– AntonioCS2009-10-23 22:28:28 +00:00Commented Oct 23, 2009 at 22:28
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You can use this script PHP: eval.in/608533anlijudavid– anlijudavid2018-02-20 22:17:47 +00:00Commented Feb 20, 2018 at 22:17
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6 Answers
Try this:
$url = "www.example.com/$link";
When string is in double quotes you can put variables inside it. Variable value will be inserted into string.
You can also use concatenation to join 2 strings:
$url = "www.example.com/" . $link;
1 Comment
David Willis
Thanks. I had tried the first already and it failed but concatenation worked a treat. $link is a double array so maybe that's why Thanks a lot!
Hate to duplicate an answer, but use single quotes to prevent the parser from having to look for variables in the double quotes. A few ms faster..
$url = 'www.example.com/' . $link;
EDIT: And yes.. where performance really mattered in an ajax backend I had written, replacing all my interpolation with concatenation gave me a 10ms boost in response time. Granted the script was 50k.
4 Comments
Rob
Is it really a few milliseconds faster? Frankly, this is precisely where variable interpolation is useful - sure, if you have a string with no variable interpolation in, use single quotes, but this seems like a ridiculous premature optimisation that slightly damages readability.
Daren Schwenke
Call me anal, but I also replace all common URL's with constants.
brianreavis
@Rob: Not to be be a moron, but... a few milliseconds is actually a huge deal in the programming world. If they stack up, you've got a slow script on your hands. Were you meaning microseconds? There's a big difference.
Rich
This is not plausible. The difference in execution speed will be micro or nano-seconds, if it is even measurable. See e.g. stackoverflow.com/questions/13620/…
Needs double quotes:
$url = "www.example.com/$link";
Comments
Alternate way:
$url = "www.example.com/{$link}";
Comments
$url = "www.example.com/$link";
Comments
It'd be helpful if you included the erroneous output, but as far as I can tell, you forgot to add double quotes:
$url = "www.example.com/$link";
You will almost certainly want to prepend "http://" to that url, as well.
