PHP Indexed Array

In PHP, arrays are linear data structures that allow to store multiple elements of the same type under a single variable which helps in saving the time and effort of creating a distinct variable for each data.

It is helpful to use arrays to compile a list of elements through which their index or key can retrieve easily.

Suppose, we want to store five names and printing them as needed. The usage of five separate string variables makes this simple. However, it would be pretty challenging for the user or developer to generate many independent variables if the number increased from five to one hundred.

In this situation, the use of an array enables us to keep all of the elements in a single variable and makes it simple to retrieve them using an index or a key. In PHP, an array is made using the array() function.

PHP includes a number of built-in functions for dealing with arrays. Arrays, along with these functions, have become a significant feature of PHP.

In PHP, there are essentially three types of arrays:

1. Numeric or Indexed Arrays: An array having a linearly-stored numeric index.

2. Associative Arrays: An array with a string index where each value can be given a particular key in place of linear storage.

3. Multidimensional Arrays: An array that may be accessed via several indices. This type of array contains one or more arrays.

Indexed Array:

An indexed array is a simple array that stores data elements against numeric indexes. Each array element is represented by an index, where 0 is the numeric value of first array element.

Syntax:

There are 2 methods to initialize an array

1. Direct array initialization
2. Distributed array initialization

Direct Array Initialization

<?php
            /* 
             1st - direct array initialization
           */
           $arrayname= array("element 1", "element 2", element 3");
  ?>

Distributed Array Initialization

<?php
$arrayname[0] = "element1";
$arrayname[1] = "element2";
$arrayname[2] = "element3";
$arrayname[3] = "element4";
$arrayname[4] = "element5";
?>

Traverse through index array

<?php
// using the for loop
for ($i = 0; $i < $size; $i++)
{
    echo $arrayname[$i], "\n";
}
?>

Examples of the Indexed Array

Program 1: Program to print an array of language names:

<?php  
$languages=array ("java", "PHP", "python", “javaScript”);  
echo "language Name: $language[0],  $language[1] , language[2], language[3]";
  ?>  

The output of the program:

Language name: java, PHP, python and javascript

Program 2: Program to print bike names:

<?php
$bikes=array (“royal Enfield”, “duke”, “ns200”, “xt” );
Echo “bike names: $bike[0], $bike[1], $bike[2], $bike[3]”;
?>

The output of the program:

Bike names: royal Enfield, duke, ns200, xt.

Examples of Distributed array initialization

Program 1: Program to print different course using indexed array:

<?php  
$course [0] ="python";  
$course [1] ="java";  
$course [2] =”PHP”; 
$course [3] =”javascript”;
echo "Course Name: $course [0]”; 
echo “$course [1]”;
echo” $course [2]”;
echo” $course [3]";  
?>  

The output of the program:

Course name: python
             Java
             PHP
             Javascript

Program 2: Program to print different names using indexed array:

<?php
$student [0] = “joe”;
$student [1] = “Janu”;
$student [2] = “Amith”;
$student [3] = “Sundar”;
echo “student names: student [0], student [1], student [2] and student [3] ”;
?>

The output of the program:

Student names: joe, Janu, Amith, Sundar

Example of Accessing PHP indexed array:

<?php
$numbers = array (“1” , “2” , “3” , “4” , “5” , “6” , “7” , “8” , “9”);
// using the for loop
for ($i = 0; $i < 9; $i++)
{
    echo $numbers[$i], "\n";
}
?>

The output of the program:

1
2
3
4
5
6
7
8
9

Program to print array using Foreach loop:

<?php
 // construct an array of data elements//
$primes = array (“2” , “3” , “5” , “7”, “11” );
foreach ( $primes as $primes )
{
 echo “$prime numbers are: $prime<br /> “;
}
?>

The output of the program:

Prime numbers are 2
3
5
7
11

Examples to count length of indexed array:

Program 1:-Program to print the count of array elements:

<?php
$numbers= array (“1” , “2” , “3” , “4” , “5” , “6” , “7” , “8” , “9” )
Echo count ($numbers);
?>

The output of the program:

Count: 9

Program 2: Program to print the count of array elements:

<?php  
$course [0] = "python";  
$course [1] = "java";  
$course [2] = “PHP”; 
$course [3] = “javascript”;
echo count($course);
?>

The output of the program:

Count: 4