fork download
copy 
  1. <?php
  2. /**
  3.  *  Whenever you create a function that has an array as a parameter you use a 
  4.  *  type-hint to make sure your parameter is of the right type.
  5.  *	
  6.  *	But is this a good idea? 
  7.  *	
  8.  *	In the same way as using is_string() excludes any objects implementing a 
  9.  *	'__toString' method, using 'Array' as type-hint excludes objects that 
  10.  *	implement the Traversable interface.
  11.  *	
  12.  *	My suggestion would be to avoid type-hinting and check for array-ishness yourself
  13.  * 
  14.  * See the code example below for an explanation.
  15.  * 
  16.  * Note: The variable naming scheme used in this code is an adaption of 
  17.  * Systems Hungarian which is explained at http://p...content-available-to-author-only...r.ca/VariableNamingConvention/
  18.  */
  19.  
  20. /**
  21.  * Check if a given variable can be treated as an Array
  22.  */
  23.  function is_arrayish ($p_aSubject) {
  24. 	$bIsArray = false;
  25.  
  26. 	if (is_array($p_aSubject) ||  $p_aSubject instanceof Traversable) {
  27. 		$bIsArray = true;
  28. 	}
  29.  
  30. 	return $bIsArray;
  31. }
  32.  
  33.  
  34. /** 
  35.  * Create an Array-ish object
  36.  */
  37. $aNumbers = ['one','two','three'];
  38. $oNumbers = new ArrayObject($aNumbers);// To save us from implementing all those ArrayAccess methods
  39.  
  40.  
  41. /**
  42.  * A function that only accepts Arrays 
  43.  */
  44. function onlyAcceptArrays(array $p_aSubject) {
  45. 	foreach($p_aSubject as $t_sItem){
  46. 		echo $t_sItem . PHP_EOL;
  47. 	}
  48. }
  49.  
  50.  
  51. /**
  52.  * A function that does accept other Arrayish types
  53.  */
  54. function acceptAllIteratorables($p_aSubject) {
  55. 	if (is_arrayish($p_aSubject) === false) {
  56. 		throw new \InvalidArgumentException(
  57. 			'Argument 1 passed to ' . __METHOD__ . ' must be of the type array or implementation of Traversable, '.
  58. 			(gettype($p_aSubject) === 'object'?'object of type '.get_class($p_aSubject):gettype($p_aSubject)) .
  59. 			' given'
  60. 		);
  61. 	} else {
  62. 		foreach($p_aSubject as $t_sItem){
  63. 			echo $t_sItem . PHP_EOL;
  64. 		}
  65. 	}
  66. }
  67.  
  68. /** 
  69.  * And now... the proof! 
  70.  */
  71.  
  72. // Works
  73. acceptAllIteratorables($oNumbers);
  74. echo '----------------------------------------' . PHP_EOL;
  75.  
  76.  
  77. try {
  78. 	// Throws Exception
  79. 	acceptAllIteratorables(new stdClass());
  80. } catch(InvalidArgumentException $eInvalidArgument){
  81. 	echo $eInvalidArgument;
  82. }
  83. echo PHP_EOL . '----------------------------------------' . PHP_EOL;
  84.  
  85. // Triggers a fatal error
  86. onlyAcceptArrays($oNumbers);
  87.  
  88. /*EOF*/
Runtime error #stdin #stdout #stderr 0.01s 20568KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
one
two
three
----------------------------------------
exception 'InvalidArgumentException' with message 'Argument 1 passed to acceptAllIteratorables must be of the type array or implementation of Traversable, object of type stdClass given' in /home/XVcl5L/prog.php:56
Stack trace:
#0 /home/XVcl5L/prog.php(79): acceptAllIteratorables(Object(stdClass))
#1 {main}
----------------------------------------
stderr
copy 
PHP Catchable fatal error:  Argument 1 passed to onlyAcceptArrays() must be of the type array, object given, called in /home/XVcl5L/prog.php on line 86 and defined in /home/XVcl5L/prog.php on line 44
https://ideone.com/KW1rtU
A better way than using the 'Array' typehint in PHP
language:
PHP (php 7.3.5)
created:
9 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!