Sort out common PHP Array Functions

Sort out common PHP Array Functions

I sorted out a complete list of PHP development Array Operations, contains basic functions for Array Operations, segmentation and filling of arrays, arrays and stacks, arrays and queues, callback functions, sorting, calculation, and other array functions.

I. basic functions of Array Operations

Key name and value of the array

Array_values ($ arr); obtain the array value
Array_keys ($ arr); get the key name of the array
Array_flip ($ arr); values in the array are exchanged with key names (if there is a duplicate, the previous one will be overwritten)
In_array ("apple", $ arr); search for apple in the array
Array_search ("apple", $ arr); search for apple in the array. If a return key name exists
Array_key_exists ("apple", $ arr); retrieves whether the specified key name exists in the array.
Isset ($ arr [apple]): retrieves whether a given key name exists in the array.

Internal pointer of Array

Current ($ arr); returns the current unit in the array
Pos ($ arr); returns the current unit in the array
Key ($ arr); returns the key name of the current unit in the array
Prev ($ arr); returns the internal pointer in the array to one
Next ($ arr); move the internal pointer in the array one by one
End ($ arr); points the internal pointer in the array to the last unit.
Reset ($ arr; point the internal pointer in the array to the first unit
Each ($ arr); returns the structure of a key name/value of the current element of the array, and moves the array pointer one byte forward.
List ($ key, $ value) = each ($ arr); obtain the key name and value of the current element of the array.

Conversion between arrays and variables

Extract ($ arr) is used to convert elements in the array into variables and import them to the current file. The key name is used as the variable name and the value is used as the variable value.
Note: (the second parameter is very important. You can refer to the Manual for use) echo $;
Compact (var1, var2, var3); Create an array with the given variable name

Ii. Segmentation and filling of Arrays

Array Segmentation

Array_slice ($ arr,); removes a segment from the array. This function ignores the key name.
Array_splice ($ arr, array ("black", "maroon"); removes a segment of the array. Unlike the previous function, the returned sequence is deleted from the original array.

Split multiple arrays

Array_chunk ($ arr, 3, TRUE); you can divide an array into multiple values. TRUE indicates that the key name of the original array is retained.

Array Filling

Array_pad ($ arr, 5, 'x'); fill an array to the specified length.

3. array and stack

Array_push ($ arr, "apple", "pear"); pushes one or more elements to the end of the array stack (inbound stack) and returns the number of inbound stack Elements
Array_pop ($ arr); pops up the last element of the array stack (Out stack)

4. arrays and queues

Array_shift ($ arr); the first element in the array is removed and returned as a result (the length of the array is reduced by 1, the other elements are moved forward by one, and the number key name is changed to the zero technology, text key name unchanged)
Array_unshift ($ arr, "a", array (1, 2); insert one or more elements at the beginning of the array

V. Callback Functions

Array_walk ($ arr, 'function', 'word'); Use user functions to process each member in the array (the third parameter is passed to the callback function)
Array_mpa ("function", $ arr1, $ arr2); can process multiple arrays (their length should be the same when two or more arrays are used)
Array_filter ($ arr, "function"); Use the callback function to filter each element in the array. If the callback function is TRUE, the current element of the array is included in the returned result array, the key name of the array remains unchanged.
Array_reduce ($ arr, "function", "*"); convert to a single-value function (* as the first value of the array)

6. Sorting Arrays

Sort arrays by element values

Sort ($ arr); sort in ascending order (by which the second parameter is sorted) Ignore the array sorting of key names
Rsort ($ arr); sort the key names in ascending order (the second parameter is sorted in what way)
Usort ($ arr, "function"); sort the values in the array using the User-Defined comparison function (the function has two parameters, 0 indicates equal, A positive number indicates that the first value is greater than the second value, and a negative number indicates that the first value is smaller than the second value.) Ignore the array sorting of key names.
Asort ($ arr); sort the key names in ascending order (in which the second parameter is sorted)
Arsort ($ arr); sort by Ascending Order (by which the second parameter is sorted)
Uasort ($ arr, "function"); sort the values in the array using the User-Defined comparison function (the function has two parameters, 0 indicates equal, positive number indicates that the first key is greater than the second, negative number indicates that the first key is smaller than the second .)

Sort arrays by key name

Ksort ($ arr); sort by key name in the forward order
Krsort ($ arr); sort by key name in reverse order
Uksort ($ arr, "function"); sort the key names in the array using the User-Defined comparison function (the function has two parameters, 0 indicates equal, A positive number indicates that the first is greater than the second, and a negative number indicates that the first is smaller than the second)

Sort by natural sorting

Natsort ($ arr); Natural sorting (ignore key names)
Natcasesort ($ arr); Natural sorting (case insensitive, key names ignored)

VII. array Calculation

Sum of array elements

Array_sum ($ arr); calculates the sum of all elements in the array.

Array Merging

Array_merge ($ arr1, $ arr2); merges two or more arrays (the same string key name, followed by the previous one, the same number key name, followed by no overwriting operation, instead, it is appended to the back)
"+" $ Arr1 + $ arr2; only the last one is retained for the same key name
Array_merge_recursive ($ arr1, $ arr2); recursive merge operation. If the array contains the same string key name, these values are merged into an array. If a value is an array, It is merged into another array according to the corresponding key name. When the array has the same Array key name, the latter value will not overwrite the original value, but will be appended

Array difference set

Array_diff ($ arr1, $ arr2); returns the result array of the difference set.
Array_diff_assoc ($ arr1, $ arr2, $ arr3); returns the result array of the difference set and compares the key names.

Array Intersection

Array_intersect ($ arr1, $ arr2); returns an array of intersection results
Array_intersect_assoc ($ arr1, $ arr2); returns an array of intersection results and compares the key names.

8. Other array Functions

Range (); Create an array containing the specified range units
Array_unique ($ arr); Removes repeated values from the array. The original key name is retained in the new array.
Array_reverse ($ arr, TRUE); returns an array in the opposite unit order to the original array. If the second parameter is TRUE, the original key name is retained.
// Srand (float) microtime () * 10000000); Random Seed trigger
Array_rand ($ arr, 2); randomly retrieves one or more elements from the array.
Shuffle ($ arr); disrupt the order of Arrays

This type of function allows you to operate arrays and interact with them in multiple ways. The essence of arrays is to store, manage, and operate a group of variables.

PHP supports one-dimensional and multi-dimensional arrays, which can be created by a user or by another function. Some specific database processing functions can generate arrays from database queries, and some functions return arrays.

Array_change_key_case-returns an array of string keys in lowercase or uppercase.

Array_chunk-divide an array into multiple

Array_combine-creates an array and uses the value of one array as its key name, and the value of another array as its value

Array_count_values-count the number of occurrences of all values in the array

Array_diff_assoc-calculate the array's difference set with index check

Array_diff_key-use the key name to compare the difference set of the calculated Array

Array_diff_uassoc-use the callback function provided by the user to perform an index check to calculate the array's difference set

Array_diff_ukey-use the callback function to compare the difference set of the calculated array with the key name

Array_diff-calculate the difference set of the array

Array_fill_keys-Fill an array with values, specifying keys

Array_fill-fill the array with the given value

Array_filter-filter elements in the array using the callback function

Array_flip-swap the keys and values in the array

Array_intersect_assoc-intersection of arrays computed by checking Indexes

Array_intersect_key-use a key name to compare and calculate the intersection of Arrays

Array_intersect_uassoc-returns the intersection of arrays computed by checking indexes and compares indexes with callback functions.

Array_intersect_ukey-use the callback function to compare key names to calculate the intersection of Arrays

Array_intersect-calculates the intersection of Arrays

Array_key_exists-check whether the given key name or index exists in the array

Array_keys-returns all the key names in the array.

Array_map-calls the callback function to the unit of the given array.

Array_merge_recursive-recursively merge one or more Arrays

Array_merge-merge one or more Arrays

Array_multisort-sorts multiple arrays or multi-dimensional arrays.

Array_pad-fill the array with a value to the specified length

Array_pop-bring up the last unit of the array (Out stack)

Array_product-calculate the product of all values in the array

Array_push-Push one or more units to the end of the array (into the stack)

Array_rand-randomly retrieve one or more units from the array

Array_reduce-Use callback functions to iteratively simplify an array to a single value

Array_reverse-returns an array with the opposite unit order.

Array_search-search for a given value in the array. If the value is successful, the corresponding key name is returned.

Array_shift-Removes elements starting with an array from the array

Array_slice-extract a segment from the array

Array_splice-removes a part of the array and replaces it with other values.

Array_sum-calculates the sum of all values in the array

Array_udiff_assoc-calculate the difference set of the array with index check and use the callback function to compare data

Array_udiff_uassoc-calculate the difference set of the array with index check, and use the callback function to compare data and indexes.

Array_udiff-use the callback function to compare data to calculate the difference set of the array

Array_uintersect_assoc-returns the intersection of arrays computed by checking indexes and compares data with callback functions.

Array_uintersect_uassoc-returns the intersection of arrays computed by checking indexes and compares data and indexes using callback functions.

Array_uintersect-calculate the intersection of arrays and use the callback function to compare data

Array_unique-Remove repeated values from the array

Array_unshift-insert one or more units at the beginning of the array

Array_values-returns all values in the array.

Array_walk_recursive-recursively applies user functions to each member in the array

Array_walk-apply user functions to each member in the array

Array-create an array

Arsort-sorts arrays in reverse order and maintains the index relationship.

Asort-sorts arrays and maintains the index relationship

Compact-create an array, including variable names and their values

Count-calculates the number of units in the array or the number of attributes in the object.

Current-returns the current cell in the array.

Each-returns the current key/value pair in the array and moves the array pointer one step forward.

End-points the internal pointer of the array to the last unit.

Extract-import the variable from the array to the current symbol table

In_array-check whether a value exists in the array

Key-Get the key name from the associated array

Krsort-Sort arrays in reverse order by key name

Ksort-sort the array by key name

List-assign values in the array to some variables

Natcasesort-use the "natural sorting" algorithm to sort arrays by case-insensitive letters

Natsort-Sort arrays using the "natural sorting" Algorithm

Next-move the internal pointer in the array to a forward position.

Alias of pos-current ()

Prev-returns the internal pointer of the array to one position.

Range-create an array containing the specified range units

Reset-point the internal pointer of the array to the first unit

Rsort-reverse sorting of Arrays

Shuffle-disrupt the Array

Alias of sizeof-count ()

Sort-sort Arrays

Uasort-sort the values in the array using the User-Defined comparison function and maintain the index Association

Uksort-sort the key names in the array using the User-Defined comparison Function

Usort-sort the values in the array using the User-Defined comparison Function