An example summary of array processing functions in PHP

#改变数组键的大小写 $arr 1=array ("a" = "Lamp", "db" = "database", "LANGUAGE" and "PHP"); Print_r (Array_change_key_case ($arr 1,case_upper)); echo " "; Print_r (Array_change_key_case ($arr 1,case_lower)); echo " "; #将一个数组分割成多个 the third parameter sets whether the key is reserved $arr 2=array (' A ', ' B ', ' C ', ' d ', ' e ', ' f ', ' G '); Print_r (Array_chunk ($arr 2,2,true)); echo " "; Print_r (Array_chunk ($arr 2,2,false)); echo " "; #array Array_diff_assoc (array $array 1, array $array 2 [, array $ ...]) returns an array, #该数组包括了所有在 Array1 but not the values in any other parameter array #键不同也算 $arr 3=array (' a ' + = ' green ', ' b ' = ' brown ', ' c ' = ' red '); $arr 4=array (' a ' = ' green ', ' yellow ', ' red '); Print_r (Array_diff_assoc ($arr 3, $arr 4)); echo " "; #array_diff (array $array 1, array $array 2 [, array $ ...]) #返回一个数组, the array includes all of the array1 but not any #其它参数数组中的值, different keys are not counted Print_r (Array_diff ($arr 3, $arr 4)); echo " "; #array_fill (int $start _index, int $num, mixed $value) The value of the #用 value parameter populates an array with num entries, #键名由 the start specified by the Start_index parameter. Print_r (Array_fill ( -5,8, "banana")); echo " "; #array_flip (Array $trans) #返回一个反转后的 array, such as the key name in trans, becomes a value, The value in the #而 trans is the key name. $arr 5=array (' a ' = ' 1 ', "b" = "2", "C", "D", "E"); Print_r (Array_flip ($arr 5)); echo " "; #array_map (callback $callback, array $arr 1 [, Array $ ...] #返回一个数组, the array contains all the cells in the arr1 that have been callback #之后的单元. The number of parameters accepted by callback should be passed to Array_map () #函数的数组数目一致. function cube ($n) { return $n * $n; } $arr 6=array (1,2,3,4,5); Print_r (Array_map ("Cube", $arr 6)); echo " "; #array_merge_recursive (array $array 1 [, Array $ ...]) #将一个或多个数组的单元合并起来, the value in an array is appended to the previous array #的后面. Returns an array as the result. If the input array has the same string key name, #则这些值会被合并到一个数组中去, this will recursively go down, so if a value itself #是一个数组, this function merges it into another array according to the corresponding entry. However, as #果数组具有相同的数组键名, the latter value will not overwrite the original value, but is appended to the #后面. $arr 7=array ("Color" =>array ("favorite" = "Red"), 5); $arr 8=array (10,array ("favorite" = "yellow", "blue")); Print_r (Array_merge_recursive ($arr 7, $arr 8)); echo " "; #array_reduce (array $input, callback $function [, int $initial] The #将回调函数 function iterates through each cell in the input array, thus the array #简化为单一的值. If an optional parameter, initial, is specified, the parameter will be treated as an array of #一个值来处理, or, if the array is empty, as the final return value. If the array is empty and no #有传递 the initial parameter, Array_reduce () returns NULL. function Rsum ($v, $w) { $v + = $w; return $v; } function Rmul ($v, $w) { $v *= $w; return $v; } $a =array (1,2,3,4,5); $x =array (); $b =array_reduce ($a, "rsum"); $c =array_reduce ($a, "Rmul", 10); $d =array_reduce ($x, "Rsum", 1); echo $b. " \t\t ". $c." \t\t ". $d." \ n "; echo " "; #array_replace (array & $array, array & $array 1 [, Array & $array 2 [, Array &$ ...]) #函数使用后面数组元素的值替换第一个 the values of array arrays. If a key exists in the first #个数组同时也存在于第二个数组, its value will be replaced by the value in the second array. If a #键存在于第二个数组, but does not exist in the first array, this is created in the first array. #元素. If a key exists only in the first array, it will remain unchanged. If more than one number of replacements are passed #组, they will be processed sequentially, followed by an array that overrides the previous value. $base =array ("Orange", "banana", "apple", "raspberry"); $replacements =array (0=> "Pineapple",4=> "cherry"); $replacements 2=array (0=> "Grape"); #print_r (Array_replace ($base, $replacements, $replacements 2)); #echo " "; #array_splice (array & $input, int $offset [, int $length [, array $ replacement]]) #把 input array is removed by the unit specified by offset and length, if replacement is provided # parameter is replaced with a cell in the replacement array. Returns an array containing the cells that have been removed # 。 Note the numeric key names in input are not retained. If length is omitted, the group is removed from the # Offset to the end of all parts. If length is specified and positive, so many cells are removed # 。 If length is specified and is negative, remove the inverse length from offset to the end of the array # So far in the middle of all the units. Tip: When replacement is given, remove the offset to # when all the cells at the end of the array, count ($input) as length. $input =array ("Red", "green", "blue", "yellow"); Array_splice ($input, 1,-1); Print_r ($input); echo " "; #key (Array & $array) #返回数组中当前单元的键名. $fruit =array ("fruit1" = "Apple", "fruit2" and "Orange", "fruit3" and "Grape", "FRUIT4" = "Apple", "fruit5" and "Apple"; while ($fruit _name=current ($fruit)) { if ($fruit _name== ' Apple ') { echo Key ($fruit). " "; } Next ($fruit); } echo " "; ?> Copy Code

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