PHP details 1 variable variables and some details

Examples of mutable variables

1<?PHP2 classFoo {3     var $bar= ' I am bar. ';4     var $arr=Array(' I am A. ', ' I am B. ', ' I am C. '));5     var $r= ' I am r. ';6 }7 8 $foo=Newfoo ();9 $bar= ' Bar ';Ten $baz=Array(' foo ', ' Bar ', ' baz ', ' Quux ')); One Echo $foo-$bar. "\ n"; A Echo $foo-$baz[1]. "\ n"; -  - $start= ' B '; the $end= ' AR '; - Echo $foo->{$start.$end} . "\ n"; -  - $arr= ' arr '; + Echo $foo-$arr[1]. "\ n"; - Echo $foo->{$arr}[1]. "\ n"; +  A?>

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Last shown as

1 I am Bar. 2 I am Bar. 3 I am Bar. 4 I am R. 5 I am B.

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Single && double quotation marks

Single quotes: Unlike double quotes and HEREDOC syntax structures, the escape sequences of variables and special characters in single-quote strings will not be replaced.

Examples are

1<?PHP2 3     $s= "Ideone";4     $s 1= ' \\Hello world $s ';//output to \hello world $s5     $s 2= "\\Hello World &&$s";//output for \hello world && Ideone6     Echo $s 1;7     Echo $s 2;8     9     //In addition, the nested part of a string that resembles a self-nesting is not iterative but empty .Ten     $s 3= "Hello World"$s 3";//Output as Hello world One     Echo $s 3; A?>

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