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Useful functions for arrays in php
Useful functions for arrays in php
Useful functions for arrays in php
Useful functions for arrays in php
Useful functions for arrays in php
Useful functions for arrays in php
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Useful functions for arrays in php

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Very Useful functions for arrays in php

Very Useful functions for arrays in php

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  • 1. Useful functions for arrays in PHP Function Explanation Examplesizeof($arr) This function returns the number Code: of elements in an array. $data = array("red", "green", "blue"); Use this function to find out how echo "Array has " . sizeof($data) . " many elements an array contains; elements"; this information is most commonly ?> used to initialize a loop counter when processing the array. Output: Array has 3 elementsarray_values($arr) This function accepts a PHP array Code: and returns a new array containing $data = array("hero" => "Holmes", "villain" only its values (not its keys). Its => "Moriarty"); counterpart is the array_keys() print_r(array_values($data)); function. ?> Use this function to retrieve all the Output: values from an associative array. Array ( [0] => Holmes [1] => Moriarty )array_keys($arr) This function accepts a PHP array Code: and returns a new array containing $data = array("hero" => "Holmes", "villain" only its keys (not its values). Its => "Moriarty"); counterpart is the array_values() print_r(array_keys($data)); function. ?> Use this function to retrieve all the Output: keys from an associative array. Array ( [0] => hero [1] => villain )array_pop($arr) This function removes an element Code: from the end of an array. $data = array("Donald", "Jim", "Tom"); array_pop($data); print_r($data);
  • 2. ?> Output: Array ( [0] => Donald [1] => Jim )array_push($arr, $val) This function adds an element to Code: the end of an array. $data = array("Donald", "Jim", "Tom"); array_push($data, "Harry"); print_r($data); ?> Output: Array ( [0] => Donald [1] => Jim [2] => Tom [3] => Harry )array_shift($arr) This function removes an element Code: from the beginning of an array. $data = array("Donald", "Jim", "Tom"); array_shift($data); print_r($data); ?> Output: Array ( [0] => Jim [1] => Tom )array_unshift($arr, $val) This function adds an element to Code: the beginning of an array. $data = array("Donald", "Jim", "Tom"); array_unshift($data, "Sarah"); print_r($data); ?> Output: Array (
  • 3. [0] => Sarah [1] => Donald [2] => Jim [3] => Tom )each($arr) This function is most often used to Code: iteratively traverse an array. Each $data = array("hero" => "Holmes", "villain" time each() is called, it returns the => "Moriarty"); current key-value pair and moves while (list($key, $value) = each($data)) { the array cursor forward one echo "$key: $value n"; element. This makes it most } suitable for use in a loop. ?> Output: hero: Holmes villain: Moriartysort($arr) This function sorts the elements of Code: an array in ascending order. String $data = array("g", "t", "a", "s"); values will be arranged in sort($data); ascending alphabetical order. print_r($data); ?> Note: Other sorting functions include asort(), arsort(), ksort(), Output: krsort() and rsort(). Array ( [0] => a [1] => g [2] => s [3] => t )array_flip($arr) The function exchanges the keys Code: and values of a PHP associative $data = array("a" => "apple", "b" => array. "ball"); print_r(array_flip($data)); Use this function if you have a ?> tabular (rows and columns) structure in an array, and you want Output: to interchange the rows and Array columns. ( [apple] => a [ball] => b )
  • 4. array_reverse($arr) The function reverses the order of Code: elements in an array. $data = array(10, 20, 25, 60); print_r(array_reverse($data)); Use this function to re-order a ?> sorted list of values in reverse for easier processing—for example, Output: when youre trying to begin with Array the minimum or maximum of a set ( of ordered values. [0] => 60 [1] => 25 [2] => 20 [3] => 10 )array_merge($arr) This function merges two or more Code: arrays to create a single composite $data1 = array("cat", "goat"); array. Key collisions are resolved in $data2 = array("dog", "cow"); favor of the latest entry. print_r(array_merge($data1, $data2)); ?> Use this function when you need to combine data from two or more Output: arrays into a single structure—for Array example, records from two ( different SQL queries. [0] => cat [1] => goat [2] => dog [3] => cow )array_rand($arr) This function selects one or more Code: random elements from an array. $data = array("white", "black", "red"); echo "Todays color is " . Use this function when you need $data[array_rand($data)]; to randomly select from a ?> collection of discrete values—for example, picking a random color Output: from a list. Todays color is redarray_search($search, This function searches the values Code:$arr) in an array for a match to the $data = array("blue" => "#0000cc", "black" search term, and returns the => "#000000", "green" => "#00ff00"); corresponding key if found. If more echo "Found " . array_search("#0000cc", than one match exists, the key of $data); the first matching value is ?> returned. Output:
  • 5. Use this function to scan a set of Found blue index-value pairs for matches, and return the matching index.array_slice($arr, This function is useful to extract a Code:$offset, $length) subset of the elements of an array, $data = array("vanilla", "strawberry", as another array. Extracting begins "mango", "peaches"); from array offset $offset and print_r(array_slice($data, 1, 2)); continues until the array slice is ?> $length elements long. Output: Use this function to break a larger Array array into smaller ones—for ( example, when segmenting an [0] => strawberry array by size ("chunking") or type [1] => mango of data. )array_unique($data) This function strips an array of Code: duplicate values. $data = array(1,1,4,6,7,4); print_r(array_unique($data)); Use this function when you need ?> to remove non-unique elements Output: from an array—for example, when Array creating an array to hold values for ( a tables primary key. [0] => 1 [3] => 6 [4] => 7 [5] => 4 )array_walk($arr, $func) This function "walks" through an Code: array, applying a user-defined function reduceBy10(&$val, $key) { function to every element. It $val -= $val * 0.1; returns the changed array. } Use this function if you need to $data = array(10,20,30,40); perform custom processing on array_walk($data, reduceBy10); every element of an array—for print_r($data); example, reducing a number series ?> by 10%. Output: Array ([0] => 9 [1] => 18 [2] => 27 [3] => 36 )

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