PHP 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 Arrays 1.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

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 $value. " "; } ?> foreach ($array as $value) { code to be executed; }

Numeric Arrays-example

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 "bar", 12 => true); echo $arr["foo"]; // bar echo $arr[12]; // 1 ?>

Associative Arrays - example 43, 32, 56, "b" => 12); //...this array array(5 => 43, 6 => 32, 7 => 56, "b" => 12); ?>

Associative Arrays - example

Associative Arrays - example 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 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 array ( "a" => "orange", "b" => "banana“,"c" => "apple”),"numbers" => array ( 1, 2,3,4,5,6), "holes" => array ("first“,5 => "second“,"thir d”)); 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 “ ”} ?>

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]. " "); } print (" "); } ?>

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]. " "); } print (" "); } ?>