1 php intro php arrays after this lecture, you should be able to: create and manipulate php arrays:...
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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.
33PHP ArrayPHP Array
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
44PHP ArrayPHP Array
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
55PHP ArrayPHP Array
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
66PHP ArrayPHP Array
Listing array elementListing array element: : forfor
$animals =$animals =
array("dog", "cat", "fish");array("dog", "cat", "fish");
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.
77PHP ArrayPHP Array
Listing Array Elements: Listing Array Elements: foreachforeach
$animals =$animals =
array("dog", "cat", "fish");array("dog", "cat", "fish");
foreach ($animals as $animal) foreach ($animals as $animal)
echo "$animal\n";echo "$animal\n";
}}
dogcatfish
88PHP ArrayPHP Array
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.
99PHP ArrayPHP Array
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.
1010PHP ArrayPHP Array
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 ) )
1111PHP ArrayPHP Array
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
1212PHP ArrayPHP Array
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
1313PHP ArrayPHP Array
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()
1414PHP ArrayPHP Array
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
1515PHP ArrayPHP Array
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);
1616PHP ArrayPHP Array
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)
1717PHP ArrayPHP Array
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', $animals);
1 (true) (false)
1818PHP ArrayPHP Array
void list(var1, var2, ...)void list(var1, var2, ...)
The elements of an array are copied into the The elements of an array are copied into the listlist
of variables of variables var1, var2,var1, var2, . . . . . .$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
1919PHP ArrayPHP Array
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.
$animals = $animals =
array('dog', 'cat', 'fish');array('dog', 'cat', 'fish');
sort($animals);sort($animals);
print_r($animals);print_r($animals);
Array( [0] = cat [1] = dog [2] = fish )
2020PHP ArrayPHP Array
asort(array), arsort(array)asort(array), arsort(array)
Sort array by values and maintain index Sort array by values and maintain index associationassociation
$animals = $animals =
array('dog', 'cat', 'fish');array('dog', 'cat', 'fish');
asort($animals);asort($animals);
print_r($animals);print_r($animals);
Array( [1] = cat [0] = dog [2] = fish )
2121PHP ArrayPHP Array
ksort(array), krsort(array)ksort(array), krsort(array)
Sort array by keys.Sort array by keys.
$animals = $animals =
array('dog' => 15, array('dog' => 15,
'cat' => 8, 'cat' => 8,
'fish' => 2);'fish' => 2);
ksort($animals);ksort($animals);
print_r($animals);print_r($animals);
Array( [cat] => 8 [dog] => 15 [fish] => 12)