1 php intro php arrays after this lecture, you should be able to: create and manipulate php arrays:...

11PHP IntroPHP Intro

PHP ArraysPHP Arrays

After this lecture, you should be able After this lecture, you should be able to:to:

Create and manipulate Create and manipulate PHP ArraysPHP Arrays:: IndexedIndexed Arrays Arrays AssociativeAssociative Arrays Arrays Array Array FunctionsFunctions

22PHP ArrayPHP Array

PHP ArraysPHP Arrays

An An indexedindexed array is similar to one provided array is similar to one provided by a conventional programming language.by a conventional programming language.

An element of an An element of an associative associative array can be array can be accessed by a keyword. accessed by a keyword.

An associative array is like a An associative array is like a dictionarydictionary with with keykey and and valuevalue..

An array element can be of any type. An array element can be of any type. An array can be An array can be heterogeneousheterogeneous with its with its

element types and structure.element types and structure. Many Many functionsfunctions manipulating an array are manipulating an array are

provided.provided.


Indexed ArrayIndexed Array$animals = $animals =

array("dog", "cat", "fish");array("dog", "cat", "fish");

echo "$animals[0]\n";echo "$animals[0]\n";

echo "$animals[2]\n";echo "$animals[2]\n";

echo "$animals\n";echo "$animals\n";

dogfishArray


Updating and Adding ElementsUpdating and Adding Elements

$animals = $animals = array("dog", "cat", "fish");array("dog", "cat", "fish");

echo "$animals[1]\n"; echo "$animals[1]\n"; $animals[1] = "$animals[1] = "tigertiger"";; echo "$animals[1]\n";echo "$animals[1]\n";

$animals[] = "beaver";$animals[] = "beaver";echo "$animals[3]\n";echo "$animals[3]\n";

cat

tiger

beaver


Associative ArrayAssociative Array

$animals = array( $animals = array(

"dog“ => 15,"cat“ => 8, "fish“ => 2);"dog“ => 15,"cat“ => 8, "fish“ => 2);

echo "$animals[cat]\n";echo "$animals[cat]\n";

$animals["bat"] = 100;$animals["bat"] = 100;

echo "$animals[bat]\n"; echo "$animals[bat]\n";

8100


Listing array elementListing array element: : forfor

$animals =$animals =


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

echo $i . "-th animal is a $animals[$i].\n";echo $i . "-th animal is a $animals[$i].\n";

}}

0-th animal is a dog.1-th animal is a cat.2-th animal is a fish.


Listing Array Elements: Listing Array Elements: foreachforeach

$animals =$animals =


foreach ($animals as $animal) foreach ($animals as $animal)

echo "$animal\n";echo "$animal\n";

}}

dogcatfish


whilewhile and and eacheach

$animals = array( $animals = array(

"dog“ => 15,"cat“ => 8, "fish“ => 2);"dog“ => 15,"cat“ => 8, "fish“ => 2);

while ($item = each($animals)) while ($item = each($animals))

print "weight of " . print "weight of " .

$item["key"] . " is " .$item["key"] . " is " .

$item["value"] . “.\n";$item["value"] . “.\n";

weight of dog is 15.weight of cat is 8.weight of fish is 2.


eacheach and and listlist$animals = array( $animals = array(

"dog“ => 15, "cat“ => 8, "fish“ = >2);"dog“ => 15, "cat“ => 8, "fish“ = >2);

while (list($key, $value)=each($animals))while (list($key, $value)=each($animals))

print "weight of $key is $value.\n";print "weight of $key is $value.\n";

weight of dog is 15.weight of cat is 8.weight of fish is 2.


Multi-Dimensional Heterogeneous Multi-Dimensional Heterogeneous ArrayArray

$books = array($books = array(

array("title“ => “A",array("title“ => “A",

"author“ => “X"),"author“ => “X"),

array("title“ => “B",array("title“ => “B",

“ “author“ => “Y",author“ => “Y",

“ “price“ => 25)price“ => 25)

););

print_r($books);print_r($books);

Array( [0] => Array ( [title] => A [author] => X ) [1] => Array ( [title] => B [author => Y [price] => 25 ) )


Nested LoopsNested Loops

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

print "$i-th book is:";print "$i-th book is:";

while ( list($key, $value) = while ( list($key, $value) =

each($books[$i]) )each($books[$i]) )

print “ $key: $value";print “ $key: $value";

print "\n";print "\n";

}}

0-th book is: title: A author: X1-th book is: title: B author: Y price: 25


String as an ArrayString as an Array

$myString = "My chars";$myString = "My chars";

echo "$myString\n"; echo "$myString\n";

echo "$myString[1]\n"; echo "$myString[1]\n";

My charsy


Array functionsArray functions count(), sizeof() count(), sizeof() in_array()in_array() array_slice() array_slice() array_reverse()array_reverse() list( )list( ) Sorting FunctionsSorting Functions

sort(), rsort()sort(), rsort() asort(), arsort()asort(), arsort() ksort(), krsort()ksort(), krsort()


count(array1)count(array1)andand sizeof(array1) sizeof(array1)

Returns the size of array Returns the size of array array1array1..

$animals = array ('dog', 'cat', 'fish');$animals = array ('dog', 'cat', 'fish');

echo count($animals);echo count($animals);

echo sizeof($animals);echo sizeof($animals);

33


array array_reverse(array1)array array_reverse(array1)

Return an array with elements in reverse order.Return an array with elements in reverse order.

Array ( [0] = fish [1] = cat [2] = dog)

$animals = $animals =

array('dog', 'cat', 'fish');array('dog', 'cat', 'fish');

$reversed = $reversed = array_reverse($animals);array_reverse($animals);

print_r($reversed);print_r($reversed);


array array_slicearray array_slice (array1, offset, length) (array1, offset, length)

Extract a slice of Extract a slice of lengthlength from from array1array1 starting starting atat

offsetoffset..

$array1 = $array1 =

array(1, 2, 3, 4, 5, 6);array(1, 2, 3, 4, 5, 6);

$subarray = $subarray =

array_slice($array1, 3, 2);array_slice($array1, 3, 2);

print_r($subarray);print_r($subarray);

Array( [0] = 4 [1] = 5)


boolean in_array(value, array1)boolean in_array(value, array1)

Check if Check if valuevalue exists in exists in array1array1..

$animals = array('dog', 'cat', 'fish');$animals = array('dog', 'cat', 'fish');

echo in_array('cat', $animals);echo in_array('cat', $animals);

echo in_array(‘monkey', $animals);echo in_array(‘monkey', $animals);

1 (true) (false)


void list(var1, var2, ...)void list(var1, var2, ...)

The elements of an array are copied into the The elements of an array are copied into the listlist

of variables of variables var1, var2,var1, var2, . . . . . .$animals = array('dog', 'cat', 'fish');$animals = array('dog', 'cat', 'fish');

list($a, $b, $c) = $animals;list($a, $b, $c) = $animals;

echo "$a, $b, $c";echo "$a, $b, $c";

dog, cat, fish


sort(array)sort(array)andand rsort(array) rsort(array)

Sort the elements in an array in increasing Sort the elements in an array in increasing oror

decreasing order.decreasing order.



sort($animals);sort($animals);

print_r($animals);print_r($animals);

Array( [0] = cat [1] = dog [2] = fish )


asort(array), arsort(array)asort(array), arsort(array)

Sort array by values and maintain index Sort array by values and maintain index associationassociation



asort($animals);asort($animals);


Array( [1] = cat [0] = dog [2] = fish )


ksort(array), krsort(array)ksort(array), krsort(array)

Sort array by keys.Sort array by keys.


array('dog' => 15, array('dog' => 15,

'cat' => 8, 'cat' => 8,

'fish' => 2);'fish' => 2);

ksort($animals);ksort($animals);


Array( [cat] => 8 [dog] => 15 [fish] => 12)

1 php intro php arrays after this lecture, you should be able to: create and manipulate php arrays:...

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