PHP ARRAY

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.

PHP ARRAY

A map is a type that associates values to keys. This type is optimized for several different uses; it can be treated as an array, list (vector), hash table (an implementation of a map), dictionary, collection, stack, queue, and probably more. As array values can be other arrays, trees and multidimensional arrays are also possible.

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.

TYPES OF ARRAY

There are 3 types of array in PHP

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• 1. Indexed Array
• 2. Associative Array
• 3. Multidimensional Array

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PHP Indexed Array�

• PHP index is represented by number which starts from 0.

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• We can store number, string and object in the PHP array.

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• All PHP array elements are assigned to an index number by default.

PHP Indexed Array�

• Syntax for creating array in PHP

Type 1 :

$season=array("summer","winter","spring","autumn");  

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Type 2 :

$season[0]="summer";  

$season[1]="winter";  

$season[2]="spring";  

$season[3]="autumn";  

​

PHP Associative Array��

• PHP allows you to associate name/label with each array elements in PHP using => symbol.

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• In it every value can be assigned with a user-defined key of string type.

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• It’s differ from numeric array in the sense that associative arrays use descriptive names for id keys.

PHP Associative Array�

• Syntax for creating array in PHP

Type 1 :

$salary=array("Sonoo"=>"350000","John"=>"450000","Kartik"=>"200000");  

Type 2 :

$salary["Sonoo"]="350000";  

$salary["John"]="450000";  

$salary["Kartik"]="200000";  

​

PHP Multidimensional Array��

• PHP multidimensional array is also known as array of arrays. It allows you to store tabular data in an array.

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• PHP multidimensional array can be represented in the form of matrix which is represented by row * column.

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• The advantage of multidimensional array is that they allow us to group related data together

PHP Multidimensional Array�

• Syntax for creating array in PHP

​

$emp = array  

  (  

  array(1,"sonoo",400000),  

  array(2,"john",500000),  

  array(3,"rahul",300000)  

  ); 

​

PHP extract() function��

• The extract( ) function is an inbuilt function of PHP, and it is used to import variables into the local symbol table from an array  

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PHP extract() function��

<?php  

    $info= array( );  

    $info['name']= "ajeet";  

    $info['office']= “msbte";  

    $info['city']= “mumbai";  

    $info['profile']= "HR";  

    extract($info);  

    echo $name;  

    echo $city;  

?>  

​

PHP compact() function��

• The compact( ) function is an inbuilt function of PHP, and it is used to create an array from variables and their values  

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PHP compact() function��

<?php

$var1 = "PHP";

$var2 = "JAVA";

$var3 = compact("var1","var2");

​

print_r($var3);

​

?>

PHP implode() function��

• PHP implode() is a string function, which joins the array elements in a string. It is a binary-safe function.
• In implode() function, parameters can be passed in any order.  
• The implode() function works same as the join() function and returns a string created from the elements of the array. Basically, this function joins all elements of array in one string.

PHP implode() function��

Syntax :

Type 1.

string implode(separator, array);

Type 2.

implode (string $glue, array $pieces)

Type 3.

implode (array $pieces)

Separator ( , : + - etc.)

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PHP explode() function��

• PHP explode() function breaks a string into an array.  
• The explode() function is a built in function in PHP used to split a string in different strings.
• The explode() function splits a string based on a string delimiter.

PHP explode() function��

Syntax :

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array explode(separator, OriginalString, NoOfElements);

PHP array_flip() function��

Syntax :

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Array_flip(array);

PHP array_flip() function Example�

<?php

�$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");�$result=array_flip($a1);�print_r($result);�

?>

PHP unset() function�

The function unset() destroys the specified variables. The behavior of unset() inside of a function can vary depending on what type of variable you are attempting to destroy.

PHP unset() function�

The function unset() destroys the specified variables. The behavior of unset() inside of a function can vary depending on what type of variable you are attempting to destroy.

syntax :- void unset ( mixed $var , mixed $vars )

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PHP unset() function Example�

<?php

$a = "Welcome TO PHP!";

echo "The value of 'a' before unset: " . $a . "<br>";

unset($a);

echo "The value of 'a' after unset: " . $a;

?>

The value of 'a' before unset: Welcome To PHP!��Warning: Undefined variable $a in C:\xampp\htdocs\php\array\unset_function.php on line 5�The value of 'a' after unset:

PHP unset() function Output�