note 11838 modified in language.operators.string by jmcastagnetto
| From: | jmcastagnetto@php.net | Date: | Thu, 16 Jan 2003 03:38:30 +0000 |
| Subject: | note 11838 modified in language.operators.string by jmcastagnetto | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-42203@lists.php.net to get a copy of this message | ||
[Editor's note: This is a good rehash of what is already explained in detail in the manual
chapter for string types, not only the different ways of defining a string are explained there, but
also the how variables are parsed and expanded, and when. You as a reader, should go and read that
section carefully. This information has been in the manual since about December 1999.]
I think difference between " and ' should be described.
With ", PHP parse contents between " and try to find PHP variables. Therefore,
When $choice has string variable 'apple'.
"your choice is $choice\n" will be
your choice is apple
There will be newline character at the end of string.
Programmer may need to use {} to resolve ambiguity of some variables. For example,
"your choice is {$object->choice}"
When programmer want to get object property. The same thing apply to multi dimensional array
variables.
"your choice is {$array['user']['choice']}"
It applies to <<< here document also.
With ', PHP does NOT parse contents between '. Therefore,
'your choice is $choice\n' will be
your choice is $choice\n
No newline at the end of string when ' is used, since PHP does not parse single quoted
strings.
Generally programmers are better to use ' when ' is applicable to avoid parse overhead.
For example, use $array['item'] rather than $array["item"]. Your script will be
executed a bit faster.
--was--
I think difference between " and ' should be described.
With ", PHP parse contents between " and try to find PHP variables. Therefore,
When $choice has string variable 'apple'.
"your choice is $choice\n" will be
your choice is apple
There will be newline character at the end of string.
Programmer may need to use {} to resolve ambiguity of some variables. For example,
"your choice is {$object->choice}"
When programmer want to get object property. The same thing apply to multi dimensional array
variables.
"your choice is {$array['user']['choice']}"
It applies to <<< here document also.
With ', PHP does NOT parse contents between '. Therefore,
'your choice is $choice\n' will be
your choice is $choice\n
No newline at the end of string when ' is used, since PHP does not parse single quoted strings.
Generally programmers are better to use ' when ' is applicable to avoid parse overhead.
For example, use $array['item'] rather than $array["item"]. Your script will be
executed a bit faster.
http://www.php.net/manual/en/language.operators.string.php