Array Tutorials in PHP, Array in PHP

It is a collection of elements of the similar and dissimilar datatype, We can store element dynamically without providing size in PHP array.

base index of the array will 0 to size-1, for example, the array has five elements then the array index will be started from 0 to 4.
Advantage of Array:-
1)  We can store multiple elements using a single variable which is easy for program code.
2)  We can easily search and sort the elements  
Type of Array:- 

 1)  Index Array:-  it will store data using an index where the base index will be started from 0 to size-1.

$arrayname = array(12,23,34,11,56,67,78);
$arrayname = array("c",12,23.45,"hello");
$arrayname[0]=12
....

Example of Array:-

<?php

$arr = array(12,23,34,11,67,78);

for($i=0;$i<count($arr);$i++)
{
    echo $arr[$i],"<br>";
}
?>

Example of Array using Foreach Loop:-

<?php

$arr = array("C",1200,"CPP",3450,"DS",56700,79800,"welcome");

for($i=0;$i<count($arr);$i++)

{

echo $arr[$i]."<br>";

}

foreach ($arr as $arr1) {

echo $arr1,"<br>";

}

?>

Program To reverse array element in PHP?

<?php
$arr = array(12,23,34,11,67,78,88,98);
for($i=count($arr)-1;$i>=0;$i--)
{
    echo $arr[$i],"<br>";
}
?>
Program to calculate the sum of array elements in PHP?
<?php
$arr = array(12,23,34,11,67,78,88,98);

$s=0;
for($i=0;$i<count($arr);$i++)
{
    $s=$s+$arr[$i];
}
echo $s;
?>
 2)   Associative Array:-
 Using this we can store elements using key=>value pair where the key is used to provide identity and value is used to provide data.
for example, rno=>1001 here rno is key and 1001 is values.
$stu = array("rno"=>1001,"sname"=>"manish kumar","branch"=>"CS","fees"=>45000);
here rno,sname,branch and fees are the keys (=> association)  

Example of Associative Array:-

<?php

$stu = array("rno"=>1001,"sname"=>"manish kumar","branch"=>"CS","fees"=>45000);
foreach($stu as $key=>$value)
{
    echo "$key  is $value"."<br>";
}  
?>
.....................................................................................
Q1)  WAP to find max, second max element in an array?

<?php
$arr = array(12,20,23,11,21,17);
$max = $arr[0];
$smax= $arr[0];
for($i=1;$i<count($arr);$i++)
{
   if($max<$arr[$i]) //12>20
   {
  $smax=$max;
    $max= $arr[$i];
   }
   else if($smax<$arr[$i] && $smax!=$max)
   {
    $smax=$arr[$i];
   }
}
echo $max,"<br>",$smax;
?>
Q2)  WAP to sort the elements of the array in asc order?
Q3) WAP to calculate the sum of even and the odd number of elements?

3)  Mixed Array:-
  it is used to collect the similar and dissimilar types of elements using index and associative array.
$x = array(10,11,"rno"=>1001,"name"=>"manish kumar");
we can print mixed array using foreach loop.
Example of Mixed array in PHP:-

<?php

$arr = array(12,23,"rno"=>1001,"CPP","JAVA","fees"=>45000,true,12.345);

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

echo "key is $key and value is $value"."<br>";

}

?>

The PRedefine function of the array in PHP:-

print_r():-  It will display the structure of array elements

$arr = array(12,23,"hello","hi")

print_r($arr);

max():-   It will display maximum element in the numerical array.

$arr = array(12,23,34,45.67)

max($arr);

min():-   It will display minimum element in the numerical array.

$arr = array(12,23,34,45.67)

min($arr);

array_sum():-  It will display sum of array elements into a numeric array

$arr = array(12,23,34,45.67)

array_sum($arr)

sort():-  it will sort array elements in ascending order

$arr = array(12,23,34,45.67,2,3)

sort($arr)

print_r($arr)

in_array():-  it will check that element is exist in an array or not.it return a boolean value.

$arr = array(12,23,34,45.67,2,3)

if(in_array(12,$x))

{

 echo "found";

}

else

{

   echo "not found";

}

is_array():-  It will check that variable is normal or array type.

$x=10;

if(is_array($x))

{

    echo "array";

}

else

{

  echo "not array";

}

array_merge():-  it is used to merge two arrays in one array.

$a = array(10,11,12);

$b = array(45,67,89,10);

$c = array_merge($a,$b);

print_r($c);

array_intersect():-   It will display common elements in two array.

$a = array(10,11,12);

$b = array(45,67,89,10);

$c = array_intersect($a,$b);

print_r($c);

array_diff():-  It will display the first array element which not exist on second.

$a = array(10,11,12);

$b = array(45,67,89,10);

$c = array_diff($a,$b);

print_r($c);

array_unique():-  It will display unique elements only and repeated elements display once.

$d = array(2,3,4,2,7,9,11,90,3,4,4,4,5);

$d1 = array_uniqe($d);

print_r($d1);

array_splice():-  It is used to split array elements using an index.

$e = array_splice($d, 6);

print_r($e);

array_chunk():-   It is used to divide one dimension array to a multidimensional array. we will provide number of elements on each row.

$d = array(2,3,4,2,7,9,11,90,3,4,4,4,5);

$e1 = array_chunk($d, 6);

print_r($e1);

array_combine():-  It is used to convert index array to associative array but both arrays should be equal size.

$key = array("rno","sname");

$val = array(1001,"xyz");

$data = array_combine($key,$val);

print_r($data);

A complete example of array predefine functions in PHP:-

<?php

$x = array(12,23,34,11,67,78);

print_r($x);

echo max($x)."<br>";

echo min($x)."<br>";

echo array_sum($x)."<br>";

sort($x);

foreach($x as $y)

{

 echo $y."<br>";

}

if(in_array(121,$x))

{

 echo "found";

}

else

{

   echo "not found";

}

$x=array();

if(is_array($x))

{

    echo "array";

}

else

{

  echo "not array";

}

$a = array(10,11,12);

$b = array(45,67,89,10);

$c = array_merge($a,$b);

print_r($c);

$a = array(10,11,12);

$b = array(45,67,89,10);

$c = array_intersect($a,$b);

print_r($c);

$a = array(10,11,12);

$b = array(45,67,89,10);

$c = array_diff($a,$b);

print_r($c);

$d = array(2,3,4,2,7,9,11,90,3,4,4,4,5);

$d1 = array_unique($d);

print_r($d1);

$e = array_splice($d, 6);

print_r($e);

echo "<br>";

$d = array(2,3,4,2,7,9,11,90,3,4,4,4,5);

$e1 = array_chunk($d, 6);

print_r($e1);

$key = array("rno","sname");

$val = array(1001,"xyz");

$data = array_combine($key,$val);

print_r($data);

?>

ASSIGNMENT:-

Create a complete mark sheet program using array?

The solution to this program:-

<?php

$marks=array("phy"=>45,"chem"=>75,"maths"=>89,"eng"=>77,"hin"=>55);

$count=0;

$total=0;

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

if($value<33)

{

$count++;

}

else

{

$total=$total+$value;

}

}

if($count==0)

{ $per=$total/5;

if($per>=33 && $per<45)

    echo "Pass with third division";

    else if($per<60)

    echo "Pass with second division";

    else

    echo "Pass with first division";       

}

else if($count==1)

{

    echo "SUPPL";

}

else

{

   echo "Failed";

}

?>

WAP to display only unique elements in an array?

example   2,2,3,4,5,6,7,5   o/p   3 4 6 7

WAP to display repeated elements in array only once?

example  2,2,3,4,5,6,7,5   o/p   2 5

WAP to merge three arrays in one array?

WAP to sort only prime elements in an array?

WAP to find second max prime elements in the array?