超越PHP - Exceed PHP: var_export

描述

mixed var_export ( mixed expression [, bool return])

此函数返回关于传递给该函数的变量的结构信息，它和 var_dump() 类似，不同的是其返回的表示是合法的 PHP 代码。

您可以通过将函数的第二个参数设置为 TRUE，从而返回变量的表示。

比较 var_export() 和 var_dump().


<pre>

<?php

$a = array (1, 2, array ("a", "b", "c"));

var_export ($a);



/* 输出：

array (

  0 => 1,

  1 => 2,

  2 => 

  array (

    0 => 'a',

    1 => 'b',

    2 => 'c',

  ),

)

*/



$b = 3.1;

$v = var_export($b, TRUE);

echo $v;



/* 输出：

3.1

*/

?>

</pre>

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var_export

php_manual_note at bigredspark dot com
16-Oct-2003 03:43

[john holmes]

True, but that method would require you to open and read
the file into a variable and then unserialize it into another
variable.



Using a file created with var_export() could simply be
include()'d, which will be less code and faster. 



[kaja]

If
you are trying to find a way to temporarily save variables into some other
file, check out serialize() and unserialize() instead - this one is more
useful for its readable property, very handy while
debugging.



[original post]

If you're like me, you're wondering
why a function that outputs "correct PHP syntax" is useful. This
function can be useful in implementing a cache system. You can var_export()
the array into a variable and write it into a file. Writing a string such
as



<?php

$string = '<?php $array = ' . $data . ';
?>';

?>



where $data is the output of var_export() can
create a file that can be easily include()d back into the script to
recreate $array. 



The raw output of var_export() could also be
eval()d to recreate the array.



---John Holmes...

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