[RESOLVED] Displaying varaible in echo.

[Earnan]

This is just a general question. I have run into problems with displaying variables in an echo statement, but the problems seem to be somewhat random.

Sometimes these seem to work:
echo "This is your number $yournumber";
echo "This is your number $array['yournumber']";

Sometimes these error, but if I re-write them as below, they work:
echo "This is your number ".$yournumber;
echo "This is your number ".$array['yournumber'];

What is the difference? Does the content of the variable matter? Is the second form a better coding style in general?

Thanks.

[laserlight]

echo "This is your number $yournumber";
echo "This is your number $array['yournumber']";

The first line, an example of variable interpolation, will always work if $yournumber exists. The second line is simply a parse error. You should write:

echo "This is your number {$array['yournumber']}";

or

echo "This is your number $array[yournumber]";

But not

echo "This is your number {$array[yournumber]}";

Since then $array[yournumber] is referenced, where yournumber is some constant.

As for:

echo "This is your number ".$yournumber;
echo "This is your number ".$array['yournumber'];

This is just string concatenation, and both always work, assuming the variables exist.

I suggest you read the PHP Manual on arrays.

Is the second form a better coding style in general?

As a coding style, it is a matter of taste. The latter (concatenation) is marginally faster than the former (variable interpolation).

[Earnan]

Ok, I think I understand it better now. The manual is sometimes confusing. Thank you.

[Installer]

A plug for this style:

echo 'This is your number ' . $array['yournumber'];

Notice how the syntax-highlighting and spacing make the variable easier to differentiate visually.

[Earnan]

Yeah, I am starting to think that is probably the better way to go. It may take a little more time writing things (and with my expereince, more time debugging because I forget a period or quotation mark somewhere 🙂 ), but it really highlights them well.