Arrays in PHP

An array is a data structure that stores one or more similar type of values in a single variable.

There are 3 types of array in PHP :

• Indexed Array
• Associative Array
• Multidimensional Array

Indexed Arrays : Index array is represented by number which starts from 0. There are two ways to create indexed arrays.

First way :

$student = array("Alokesh", "Ashim", "Mridul");

Second way :

or the index can be assigned manually:
$student[0] = "Alokesh";
$student[1] = "Ashim";
$student[2] = "Mridul"; 

Example :

<?php
$student = array("Alokesh", "Ashim", "Mridul");
echo "Students name : ".$student[0].", ".$student[1].", ".$student[2]."<br>";

/* count() function is used to return the length of an array */
echo " Length of the array is ".count($student);
?>

Output :

Students name : Alokesh, Ashim, Mridul
Length of the array is 3

Or

<?php
$student[0]="Alokesh";
$student[1]="Ashim";
$student[2]="Mridul";
echo "Students name : ".$student[0].", ".$student[1].", ".$student[2]."<br>";
?>

Output :

Students name : Alokesh, Ashim, Mridul

Associative Array : Associative arrays are arrays that use named keys that you assign to them. There are two ways to create an associative array.

First way :

$age = array("Alokesh"=>"23", "Ashim"=>"22", "Mridul"=>"22");

Second way :

$age["Alokesh"] = "23";
$age["Ashim"] = "22";
$age["Mridul"] = "22";

Example :

<?php
$age = array("Alokesh"=>"23", "Ashim"=>"22", "Mridul"=>"22");
echo "Alokesh is ".$age["Alokesh"]." year old <br>";
echo "Ashim is ".$age["Ashim"]." year old <br>";
echo "Mridul is ".$age["Mridul"]." year old";
?>

Output :

Alokesh is 23 year old
Ashim is 22 year old
Mridul is 22 year old

Multidimensional Array : A multidimensional array is an array containing one or more arrays. Multidimensional array can be represented in the form of matrix which is represented by row * column.

Let's see a simple example of  multidimensional array to display following tabular data.

ID	Name	Salary
1	Rahul	45000
2	Pankaj	38000
3	Parag	40000

Using array :

<?php
$client = array
  (
  array(1,"Rahul",45000),
  array(2,"Pankaj",38000),
  array(3,"Parag",40000),
  );

  for ($row = 0; $row < 3; $row++) { 
  for ($col = 0; $col < 3; $col++) { 
    echo $client[$row][$col]."  "; 
  } 
  echo "<br/>"; 
}
?>

Output :

1 Rahul 45000
2 Pankaj 38000
3 Parag 40000