Interview GURU

What is the difference between indexed and associative array?

PHP Arrays
PHP array is an ordered map (contains value on the basis of key). It is used to hold multiple values of similar type in a single variable.

Advantage of PHP Array

Less Code: We don't need to define multiple variables.

Easy to traverse: By the help of single loop, we can traverse all the elements of an array.

Sorting: We can sort the elements of array

PHP Array Types

There are 3 types of array in PHP.
  1. Indexed Array
  2. Associative Array
  3. Multidimensional Array

PHP Indexed Array

PHP index is represented by number which starts from 0. We can store number, string and object in the PHP array. All PHP array elements are assigned to an index number by default.

There are two ways to define indexed array:

1st way:
$season=array("summer","winter","spring","autumn");  

2nd way:
$season[0]="summer";  
$season[1]="winter";  
$season[2]="spring";  
$season[3]="autumn";  

Example

File: array1.php
<?php  
$season=array("summer","winter","spring","autumn");  
echo "Season are: $season[0], $season[1], $season[2] and $season[3]";  
?>  
Output:
Season are: summer, winter, spring and autumn

File: array2.php
<?php  
$season[0]="summer";  
$season[1]="winter";  
$season[2]="spring";  
$season[3]="autumn";  
echo "Season are: $season[0], $season[1], $season[2] and $season[3]";  
?>  
Output:
Season are: summer, winter, spring and autumn