Php > Arrays

Arrays and Associative Arrays

Arrays and Associative Arrays

Arrays are one of the most powerful parts of the PHP language.You can initialize 
your array in following manner. 

<?php 
$ar[]="Visual"; 
$ar[]="Basic";$ar[]="is g8"; 
print_r($ar); 
?> 

You can also declare using a list.$ar=array("Visual","Basic","Scripting"); 

Printing a List with commas 
<?php 
$ar=array("Janifer","Anna","Hingis"); 
$ar=implode(",",$ar); 
print $ar; 
?> 

array_splice 

array_splice is used to shrink an array.array_splice(array init,int start,int 
lenth,aray repl.) 

<?php 
$ar=array("Janifer","Anna","Hingis"); 
$ar=array_splice($ar,2); // it will remove first two elements 
$ar=implode(",",$ar); 
print $ar; 
?> 


array_unique 
array_unique eliminates duplicate entries from your array. 

<?php 
$str=array_unique($ar); 
?> 

Returning the Current Element from an Array 

Use PHP in-built current function or loop through array. 
<? 
$current_element=current($ar); 
?> 

count 
===== 
function is used to count no of item in an array. 
<?php 
for ($i=0;$i<count($ar);$i++){ 
print $ar[$i]; 
} 
?> 

foreach 
======= 
<? 
php foreach($ar as $element) { 
print $element; 
} 
?> 

Finding Elements in One Array but Not Another 
============================================= 
Use array_diff() function to find the difference. 

<? 
php$ar1=array("Green","Red","White"); 
$ar2=array("Red","Blue","Violet"); 
$diff=array_diff($ar1,$ar2); 
foreach ($diff as $element){ 
print $element; 
print "<br>"; 
} 
?> 

Appending an Array to another 
============================= 
Use Built-in array_merge function. 
<?php 
$ar1=array("Green","Red","White"); 
$ar2=array("Red","Blue","Violet"); 
$add=array_merge($ar1,$ar2); 
foreach ($add as $element){print $element; 
print "<br>";} 
?> 

You can also + sign to merge the files.$add=$ar1+$ar2;If you dont want to lose 
elements that are same in both arrays, you can use the array_merge_recursive() 
function. 

Reversing an array 
================== 
use built-in array_reverse function. 
<?php 
$ar=array("Green","Red","White"); 
$ar=array_reverse($ar); 
foreach ($ar as $element){ 
print $element; 
print "<br>"; 
} 
?> 

ASSICIATIVE ARRAY 
================= 
Associative array has "String Index Association". Associative array represent 
relationship.For example "Sachin is Cricket Star", you can represent it as 
<? 
$star['Cricket']="Sachin"; 
?> 
Constructing associative array is similar to Normal array but you have to 
specify both the value and the key. 
<? 
$star=array("Cricket"=>"Sachin"); 
?> 

Adding new elements in an associative array 
=========================================== 
<?php 
//to add a star 
$stars=array("Kapil"=>"Cricket, "Anna"=>"Tenis", "Maradona"=>"Football"); 
$stars["MJ"]="BasketBall"; 
?> 

Associative Array - Testing key presence 
======================================== 
Use PHP's built-in function isset() 
<?php 
$stars=array("Kapil" => "Cricket", "Anna" => "Tenis", "Maradona" => "Football"); 
if (isset($stars["Kapil"])) { 
echo "OK ..."; 
}else{ 
echo "Not Exist ..."; 
} 
?> 

Deleting elements in an associative array 
========================================= 
Use unset buit-in function for deleting n element , you can pass a single element or 
a whole array into it. 

<?php 
$stars=array("Kapil" => "Cricket", "Anna" => "Tenis", "Maradona" => "Football"); 
unset($stars[Kapil],$stars[Anna]); 
foreach($stars as $nam=>$play){ 
print $nam; 
} 
?> 

Moving through an Associative Array 
=================================== 
use foreach loop 
<?php 
foreach ($ar as $key=>$value){ 
//operations 
} 
?> 
*To merge two arrays you can use array_merge() function or simple use +sign 
$ar1+$ar2