PHP Array Concepts with Easy Examples

PHP Array Concepts with Easy Examples

Here I have discussed about array concepts in php.

I hope people reading this blog must have known the basics of Php

just for reference i am giving small introduction of what PHP is??

PHP ==' Hypertext Preprocessor'.

Open Source, Serverside scripting Language.

Used to generate dynamic Web pages.

PHP scripts resides between reserved PHP tags.



This allows the programmer to embed PHP scripts within HTML pages.

Structurally similar to C/C++

Supports Procedural and OOP concept.




All PHP statements ends with a semicolon



PHP variables must begin with a "$" sign.

ARRAYS IN PHP

Now comin array concepts:

Definition 1:
An array is simply a collection of keys and their associated values. In PHP, the key can be either an integer or string, while the value can be any PHP data type.


In simple words array can be defined as follows.

Definition 2:
Arrays are special data types. Despite of other normal variables an array can store more than one value.

CREATE AN ARRAY:

In PHP, Arrays are created using the array() function:

$blankArray = array();
Here $blankArray is a variable in to which we are storing the array values.
array(//give no of array elements.)

Initializing Array:

An array can be initialized with a set of values by passing the values as parameters to the array() function: $anArray = array('A', 'B', 'C', 'D');

When initializing an array in the manner above, the values are automatically associated with integer keys in sequential order, starting at zero. The keys can be specified explicitly using the => operator:

$myArray = array('firstKey' => 'A'

	, 'secondKey' => 'B'

	, 19 => 'C'

	, 22 => 'D');



Retriving values from an array

Values can be retrieved from an array using the square bracket syntax below. If the key is a string, it is considered good practice to always use quotes.

echo $myArray['firstKey']; // A echo $myArray[19]; // C

Adding Values to an Array

Values can be added to an array using the syntax below:

$myArray['anotherKey'] = 'E';

If a key is not specified, the value will be associated with the largest previously assigned integer key plus one.

// If the largest integer key was 22, the key

// for the value below would be 23.

$myArray[] = 'F';

Removing Values from an Array

Use the unset() function to remove an item from an array.

unset($myArray[22]);  // Removes the item with key 22

Iterating Through an Array

The foreach operator can be used to iterate over the items in an array.

// Display the current contents of the array

foreach($myArray as $key => $value) {

echo $key . ' => ' . $value . '

';

}

Multi-Dimensional Arrays

In PHP, a multi-dimensional array can be created by making an array containing other arrays as values.

$multiDimensionalArray = array(

'A' => array(0 => 'red', 2 => 'blue', 3 => 'green'),

'B' => array(1 => 'orange', 2 => 'black'),

'C' => array(0 => 'white', 4 => 'purple', 8 => 'grey')

);



echo $multiDimensionalArray['A'][3]; // green

echo $multiDimensionalArray['C'][8]; // grey

here i have discussed few array concepts with their syntax.

I hope this post would give you the basic concepts of what an array is and how is it created and used.