php arrays. outline o what is array in php ? o numeric array o associative array o multidimensional...

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Arrays

Outline

o What is array in PHP ?

o Numeric array

o Associative array

o Multidimensional array

What is array in PHP ?

A variable is a storage area holding a number or text.

The problem is, a variable will hold only one value.

An array is a special variable, which can store

multiple values in one single variable.

What is array in PHP ?

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 best solution here is to use an array!

An array can hold all your variable values under a single

name. And you can access the values by referring to the array

name.

Each element in the array has its own index so that it can be

easily accessed.

Kind of arrays in PHP

Numeric array - An array with a numeric index

Associative array - An array where each ID key is

associated with a value

Multidimensional array - An array containing one or

more arrays

Numeric Arrays

• A numeric array stores each array element

with a numeric index.

• There are two methods to create a numeric

array:

Numeric Arrays1. In the following example the index are automatically assigned (the index starts at 0):

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

2. The following example we assign the index manually:

$cars[0]="Saab";

$cars[1]="Volvo";

$cars[2]="BMW";

$cars[3]="Toyota";

$array_name = array(val1, val2, val3, val4,……);

Numeric Arrays-example<?php

$cars[0]="Saab";

$cars[1]="Volvo";

$cars[2]="BMW";

$cars[3]="Toyota";

echo $cars[0] . " and " . $cars[1] . " are Swedish cars.";

?>

Numeric Arrays-example<?php

$array = array(1, 2,3,4,5,6,7,8,9);

for ($i = 0; $i < 9; $i++)

{

echo “Number : “. $array[$i];

}

?>

Print_r()

• Print construction of array as group of locations and the value stored in it

Print_r($array );

Print_r()<?php

$arr = array(1,2,3,4,5);

Print_r($arr);

?>

Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 )

Count()• this is build in function , that count number of value store in array or number of character in string .

Count($variable );

Numeric Arrays-example<?php

$array = array(“M”, ”u”,”n”,”e”,”e”,”r”);

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

{

echo $array[$i];

}

?>

foreach

<?php

$x=array("one","two","three");

foreach ($x as $value)

  {

  echo $value . "<br />";

  }

?>

foreach ($array as $value) { code to be executed; }

Numeric Arrays-example<?php

$colors = array('red', 'blue', 'green', 'yellow');

foreach ($colors as $color) {

echo "Do you like $color?\n";

}

?>

Find in Array

- This function return true if the $search found in $orginal_data , otherwise return false.

in_array($search , $orginal_data)

Find in Array

<?php

$os = array("Mac", “W7", “W8", "Linux");

if (in_array(“XP", $os)) {

echo "Got XP";

}

if (in_array(“Mac", $os)) {

echo "Got Mac";

}

?>

Associative Arrays

• An associative array, each ID key is associated with a value.

• When storing data about specific named values, a numerical array is not always the best way to do it.

• With associative arrays we can use the values as keys and assign values to them.

Associative Arrays

• $ages = array("Peter"=>32, "Quagmire"=>30, "Joe"=>34);

or• $ages['Peter'] = "32";

$ages['Quagmire'] = "30";

$ages['Joe'] = "34";

$array_name= array($index1=>$val1, $index1=>$val1,…..);

Associative Arrays <?php

$arr = array("foo" => "bar", 12 => true);

echo $arr["foo"]; // barecho $arr[12]; // 1?>

Associative Arrays - example<?php

// This array is the same as ...

array(5 => 43, 32, 56, "b" => 12);

// ...this array

array(5 => 43, 6 => 32, 7 => 56, "b" => 12);

?>

Associative Arrays - example<?php

$ages['Peter'] = "32";

$ages['Quagmire'] = "30";

$ages['Joe'] = "34";

echo "Peter is " . $ages['Peter'] . " years old.";

?>

Associative Arrays - example<?php

$arr = array(5 => 1, 12 => 2);

$arr[] = 56; // This is the same as $arr[13] = 56;

// at this point of the script

$arr["x"] = 42; // This adds a new element to

// the array with key "x"

unset($arr[5]); // This removes the element from the array

unset($arr); // This deletes the whole array

?>

Associative Arrays - example<?php

$arr = array("somearray" => array(6 => 5, 13 => 9, "a" => 42));

echo $arr["somearray"][6]; // 5

echo $arr["somearray"][13]; // 9

echo $arr["somearray"]["a"]; // 42

?>

Multidimensional Arrays

• In a multidimensional array, each element in the main array can also be an array. And each element in the sub-array can be an array,

$myArray = array( array( value1, value2, value3 ), array( value4, value5, value6 ), array( value7,

value8, value9 ) );

Multidimensional Arrays<?php

$fruits = array ( "fruits"  => array ( "a" => "orange", "b" => "banana“,"c" => "apple”),"numbers" => array ( 1, 2,3,4,5,6), "holes"   => array ("first“,5 => "second“,"third”));

echo $fruits["holes"][5];    // prints "second"

echo $fruits["fruits"]["a"]; // prints "orange"

?>

Multidimensional Arrays

<?php

$families = array(“capital"=>array(“A“,“B“,“C”),

  “small"=>array(“a”, “b”, “c”),

“number"=>array(“1“,“2“,”3”));

foreach($families as $value)

{foreach($value as $values)

{echo $values.” ”;}

Echo “<br/>”}

?>

Multidimensional Arrays<?php

$try[] = array("11", "12", "15", "22", "41", "42");

$try[] = array("6", "7", "16", "17", "22", "23");

$count = count ($try);

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

{

$countmore=count($try[0]);

for ($j=0; $j < $countmore; $j++)

{

print ("i$i j$j " . $try[$i][$j] . "<br> ");

}

print ("<br>");

}

?>

Multidimensional Arrays<?php

$try[] = array("11", "12", "15", "22", "41", "42");

$try[] = array("6", "7", "16", "17", "22", "23"); $count = count ($try); for ($i=0; $i<$count; $i++)

{

$countmore=count($try[0]);

for ($j=0; $j < $countmore; $j++)

{ print ("i$i j$j " . $try[$i][$j] . "<br> "); }

print ("<br>");

}

?>