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PHP Tutorial

PHP Introduction

PHP 5 Installation

PHP 5 Syntax

PHP 5 Variables

PHP 5 echo and print Statements

PHP 5 Data Types

PHP 5 String Functions

PHP 5 Constants

PHP Arithmetic Operators

PHP 5 if...else...elseif Statements

PHP 5 switch Statement

PHP 5 while Loops

PHP 5 for Loops

PHP 5 Functions

PHP 5 Arrays

PHP 5 Sorting Arrays

PHP 5 Superglobals

PHP Forms

PHP 5 Form Handling

PHP 5 Form Validation

PHP 5 Forms - Required Fields

PHP 5 Forms E-mail /URL

PHP Form Complete

PHP Advanced

PHP 5 Multidimensional Arrays

PHP 5 Date and Time

PHP Include Files

PHP File Handling

PHP File Open/Read

PHP File Create/Write

PHP File Upload

PHP Cookies

PHP Sessions

PHP E-mail

PHP Secure E-mails

PHP Error Handling

PHP Exception Handling

PHP Filter

PHP Database

PHP MySQL Introduction

PHP MySQL Connect

PHP Create DB/Tables

PHP MySQL Insert Into

PHP MySQL Select

PHP MySQL Where

PHP Order By

PHP Update

PHP Delete

PHP ODBC

 

PHP 5 Arrays

An array stores multiple values in one single variable:

Example

<?php
$cars=array("Volvo","BMW","Toyota");
echo "I like " . $cars[0] . ", " . $cars[1] . " and " . $cars[2] . ".";
?>

What is an Array?

An array is a special variable, which can hold more than one value at a time.

If you have a list of items (a list of car names, for example), storing the cars in single variables could look like this:

$cars1="Volvo";
$cars2="BMW";
$cars3="Toyota";

However, what if you want to loop through the cars and find a specific one? And what if you had not 3 cars, but 300?

The solution is to create an array!

An array can hold many values under a single name, and you can access the values by referring to an index number.


Create an Array in PHP

In PHP, the array() function is used to create an array:

array();

In PHP, there are three types of arrays:

  • Indexed arrays - Arrays with a numeric index
  • Associative arrays - Arrays with named keys
  • Multidimensional arrays - Arrays containing one or more arrays

PHP Indexed Arrays

There are two ways to create indexed arrays:

The index can be assigned automatically (index always starts at 0):

$cars=array("Volvo","BMW","Toyota");

or the index can be assigned manually:

$cars[0]="Volvo";
$cars[1]="BMW";
$cars[2]="Toyota";

The following example creates an indexed array named $cars, assigns three elements to it, and then prints a text containing the array values:

Example

<?php
$cars=array("Volvo","BMW","Toyota");
echo "I like " . $cars[0] . ", " . $cars[1] . " and " . $cars[2] . ".";
?>

Get The Length of an Array - The count() Function

The count() function is used to return the length (the number of elements) of an array:

Example

<?php
$cars=array("Volvo","BMW","Toyota");
echo count($cars);
?>

Loop Through an Indexed Array

To loop through and print all the values of an indexed array, you could use a for loop, like this:

Example

<?php
$cars=array("Volvo","BMW","Toyota");
$arrlength=count($cars);

for($x=0;$x<$arrlength;$x++) {
  echo $cars[$x];
  echo "<br>";
}
?>

PHP Associative Arrays

Associative arrays are arrays that use named keys that you assign to them.

There are two ways to create an associative array: 

$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");

or:

$age['Peter']="35";
$age['Ben']="37";
$age['Joe']="43";

The named keys can then be used in a script:

Example

<?php
$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");
echo "Peter is " . $age['Peter'] . " years old.";
?>

Loop Through an Associative Array

To loop through and print all the values of an associative array, you could use a foreach loop, like this:

Example

<?php
$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");

foreach($age as $x=>$x_value) {
  echo "Key=" . $x . ", Value=" . $x_value;
  echo "<br>";
}
?>