PHP: Always use an index to add a values to an array

 

Demand

Always identify the array index when manipulating the array directly

Description

Whenever you are adding a new item to the array you must add an index so that php does not need to recalculate the size of the array to identify in which position the new content will be added.

Examples

1:  # Bad code:  
2:  do {  
3:    $array[] = $newItem;  
4:  } while(!feof($fp));  
5:    
6:  # Good code  
7:  $array = [];  
8:  $index = 0;  
9:  do {  
10:    $array[$index++] = $newItem;  
11:  } while(!feof($fp));  

Examples Explanation

When instantiating a new item in an array in the "bad example" php will identify that you expect the item to be added to the end of the array, since array is a primitive type and has no attributes php always needs to call a calculation function to identify the current size of the array before trying to add a new item to the end of it.

By monitoring the growth of the array in an external variable and automatically reference which position will be the new position, it speeds up the instantiating as it avoids constantly recalculating the size of the array. As seen in the "good sample".