PHP array operations _ PHP-php Tutorial

This article mainly introduces the PHP array operation class, which involves php operations related to array deletion, conversion, grouping, sorting, and so on. it has some reference value, for more information about PHP array operations, see the example in this article. Share it with you for your reference. The details are as follows:

Class ArrayHelper {/*** delete blank elements from the array (including elements with only blank characters) ** usage: * @ code php * $ arr = array ('', 'test', ''); * ArrayHelper: removeEmpty ($ arr); ** dump ($ arr ); * // in the output result, only 'test' * @ endcode ** @ param array $ array to be processed by arr * @ param boolean $ whether trim calls the trim function */static function removeEmpty (& $ arr, $ trim = TRUE) {foreach ($ arr as $ key => $ value) {if (is_array ($ value) {self :: removeEmpty ($ arr [$ key]);} Else {$ value = trim ($ value); if ($ value = '') {unset ($ arr [$ key]);} elseif ($ trim) {$ arr [$ key] = $ value ;}}}/*** returns all values of the specified key from a two-dimensional array ** usage: * @ code php * $ rows = array (* array ('id' => 1, 'value' => '1-1 '), * array ('id' => 2, 'value' => '2-1'), *); * $ values = ArrayHelper: getCols ($ rows, 'value'); ** dump ($ values); * // The output result is * // array (* // '1-1 ', * // '2-1', * //) * @ endcode ** @ p Aram array $ arr data source * @ param string $ col the key to be queried ** @ return array contains an array of all values of the specified key */static function getCols ($ arr, $ col) {$ ret = array (); foreach ($ arr as $ row) {if (isset ($ row [$ col]) {$ ret [] = $ row [$ col] ;}} return $ ret;}/*** converts a two-dimensional array into a HashMap and returns the result. ** usage 1: * @ code php * $ rows = array (* array ('id' => 1, 'value' => '1-1 '), * array ('id' => 2, 'value' => '2-1'), *); * $ hashmap = ArrayHelper :: ToHashmap ($ rows, 'id', 'value'); ** dump ($ hashmap ); * // The output result is * // array (* // 1 => '1-1', * // 2 => '2-1 ',*//) * @ endcode ** if the $ valueField parameter is omitted, each item in the conversion result is an array containing all the data of this item. ** Usage 2: * @ code php * $ rows = array (* array ('id' => 1, 'value' => '1-1 '), * array ('id' => 2, 'value' => '2-1'), *); * $ hashmap = ArrayHelper: toHashmap ($ rows, 'id'); ** dump ($ hashmap); * // The output result is * // array (* // 1 => array ('id' => 1, 'value' => '1-1'), * // 2 => array ('id' => 2, 'value' => '2-1 '), * //) * @ endcode ** @ param array $ arr data source * @ param string $ the key value of keyField for conversion * @ param strin G $ valueField key value ** @ return array converted HashMap style array */static function toHashmap ($ arr, $ keyField, $ valueField = NULL) {$ ret = array (); if ($ valueField) {foreach ($ arr as $ row) {$ ret [$ row [$ keyField] = $ row [$ valueField] ;}} else {foreach ($ arr as $ row) {$ ret [$ row [$ keyField] = $ row;} return $ ret;}/*** groups a two-dimensional array by the value of the specified field ** usage: * @ endcode ** @ param array $ arr data source * @ param string $ ke The key name ** @ return array result */static function groupBy ($ arr, $ keyField) {$ ret = array (); foreach ($ arr as $ row) {$ key = $ row [$ keyField]; $ ret [$ key] [] = $ row;} return $ ret ;} /*** convert a two-dimensional array of a plane to a tree structure based on the specified field *** to obtain the subtree with any node as the root, you can use the $ refs parameter: * @ code php * $ refs = null; * $ tree = ArrayHelper: tree ($ rows, 'id', 'parent', 'nodes ', $ refs ); ** // The node whose output id is 3 and all its subnodes ** $ id = 3; * dump ($ Refs [$ id]); * @ endcode ** @ param array $ arr data source * @ param string $ keyNodeId node ID field name * @ param string $ keyParentId node parent ID field name * @ param string $ keyChildrens field name * @ param boolean $ whether refs contains a node reference in the returned result ** return array */static function toTree ($ arr, $ keyNodeId, $ keyParentId = 'parent _ id', $ keyChildrens = 'childrens', & $ refs = NULL) {$ refs = array (); foreach ($ arr as $ offset => $ row) {$ Rr [$ offset] [$ keyChildrens] = array (); $ refs [$ row [$ keyNodeId] = & $ arr [$ offset];} $ tree = array (); foreach ($ arr as $ offset => $ row) {$ parentId = $ row [$ keyParentId]; if ($ parentId) {if (! Isset ($ refs [$ parentId]) {$ tree [] = & $ arr [$ offset]; continue ;}$ parent = & $ refs [$ parentId]; $ parent [$ keyChildrens] [] = & $ arr [$ offset];} else {$ tree [] = & $ arr [$ offset] ;}} return $ tree ;} /*** split the tree array into a flat array ** this method is the inverse operation of the tree () method. ** @ Param array $ tree-like array * @ param string $ keyChildrens contains the key name of the subnode ** @ return array expanded array */static function treeToArray ($ tree, $ keyChildrens = 'childrens') {$ ret = array (); if (isset ($ tree [$ keyChildrens]) & is_array ($ tree [$ keyChildrens]) {foreach ($ tree [$ keyChildrens] as $ child) {$ ret = array_merge ($ ret, self: treeToArray ($ child, $ keyChildrens ));} unset ($ node [$ keyChildrens]); $ ret [] = $ tree;} else {$ ret [] = $ tree;} return $ ret ;} /*** sort arrays by specified keys ** @ endcode ** @ param array $ array * @ param string $ key for sorting by keyname * @ param int $ dir sorting direction ** @ return array */static function sortByCol ($ array, $ keyname, $ dir = SORT_ASC) {return self: sortByMultiCols ($ array, array ($ keyname => $ dir ));} /*** sort a two-dimensional array BY multiple columns, similar to order by ** in SQL statements: * @ code php * $ rows = ArrayHelper :: sortByMultiCols ($ rows, array (* 'parent' => SORT_ASC, * 'name' => SORT_DESC ,*)); * @ endcode ** @ param array $ array to be sorted * @ param array $ args sort key ** @ return array sorted array */static function sortByMultiCols ($ rowset, $ args) {$ sortArray = array (); $ sortRule = ''; foreach ($ args as $ sortField => $ sortDir) {foreach ($ rowset as $ offset => $ row) {$ sortArray [$ sortField] [$ offset] = $ row [$ sortField];} $ sortRule. = '$ sortArray [\''. $ sortField. '\'], '. $ sortDir. ',';} if (empty ($ sortArray) | empty ($ sortRule) {return $ rowset;} eval ('Array _ multisort ('. $ sortRule. '$ rowset);'); return $ rowset ;}}

I hope this article will help you with php programming.