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The Concatenation Operator


legacy800
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Hi,In Examples like this:echo $cars[0] . " and " . $cars[1] . " are Swedish cars.";I understand how the concatenation operator works in examples like these , but in examples like the one below why is it needed?Couldn't really find a good answer in the tutorials.echo "<td>" . $row['website'] . "</td>";Greetings,A php noob

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PHP variables can all be resolved inside double quotes (and heredocs, FWIW). But array elements require a special syntax. The altrernative to your example is this:"<td>{$row['website']}</td>";Some developers dislike the curly braces, I think. It's a matter of personal style more than anything.

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I understand how the concatenation operator works in examples like these , but in examples like the one below why is it needed?
Is it not because because you are concatenating string literals and variables in both instances?Frankly I see no difference between the two examples that you provide. In both cases what is contained in quotation marks becomes a fixed part of the HTML document, and what is preceded by a dollar sign is a PHP variable whose value changes according to some statement written in PHP.Roddy
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Like me!
I actually like the ability to interpolate variables. Sometimes I get a better idea what my finished string will look like, especially when I'm building SQL queries. But those curly braces are annoying. I often assign array elements to a scalar variable before assembling strings just so I can make them more readable. Edited by Deirdre's Dad
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I actually like the ability to interpolate variables. Sometimes I get a better idea what my finished string will look like, especially when I'm building SQL queries. But those curly braces are annoying. I often assign array elements to a scalar variable before assembling strings just so I can make them more readable.
I like interpolation too, but I personally prefer having curly braces around variables that would be interpolated. When you mix several layers at once (e.g. PHP inserting PHP code into MySQL... an unlikely case, I know, but still), it can sometimes be confusing whether a certain special character is part of one layer or another. Curly braces make it somewhat more explicit - you know that if there's "{$", you have a variable name in place, whereas if you watch out only for "$", you also need to keep in mind the "\$" sequence... then again, having "\{$" is also a possible sequence, but even then, you still have interpolation occuring... only with "{" in front of the interpolated variable value.
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I like interpolation too, but I personally prefer having curly braces around variables that would be interpolated. When you mix several layers at once (e.g. PHP inserting PHP code into MySQL... an unlikely case, I know, but still), it can sometimes be confusing whether a certain special character is part of one layer or another. Curly braces make it somewhat more explicit - you know that if there's "{$", you have a variable name in place, whereas if you watch out only for "$", you also need to keep in mind the "\$" sequence... then again, having "\{$" is also a possible sequence, but even then, you still have interpolation occuring... only with "{" in front of the interpolated variable value.
That's exactly the problem. There's too much looking to do. When I see this: "variable: ".$varI know that means I'm using a variable and I want to see the variable's data when it's printed.When I see this: "variable: $variable"It isn't clear to me that this should also print the variable's data. It requires a more careful eye. (Especially with syntax coloring :) )And as far as the different layers go...well, you don't have to worry about your escape sequences and what pattern to look for.Just look for this: 'var: '.$var.' with $var'So simple! :) Edited by jkloth
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I prefer concatenation to interpolation too. My point was that when I do use interpolation (which I use for simpler cases, mostly), I prefer to use curly braces than not.

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