Summary of PHP array operation functions_PHP tutorial

The most commonly used data structure in PHP is arrays. Arrays can help us solve a large part of programming problems. In fact, there are many array operations that we don’t need to write ourselves. The system already comes with related functions. Below we introduce some functions about PHP array operations, maybe some of which you have not heard of.

1. Search for a specific value in an array, returning TRUE if found otherwise returning FALSE

boolean in_array(mixed needle,array haystack[,boolean strict])

2. Find a specified key in the array, return TRUE if found, otherwise return FALSE

boolean array_eky_exists(mixed key,array array)

3. Search for a specific value in an array, returning TRUE if found otherwise returning FALSE

boolean array_search(mixed needle,array haystack[,boolean strict])

4. Get a new array composed of all keys of the array

array array_keys(array array[,mixed search_value])

5. Get a new array composed of all values ​​in the array

array array_values(array array)

6. Determine array size

integer count(array array[,int mode])
integer sizeof(array array[,int mode])

7. Count the frequency of occurrence of array elements

array array_count_values(array array)

8. Delete duplicate values ​​in the array and return an array composed of unique values

array array_unique(array array)

9. Reverse the order of the array elements. If preserve_key is TRUE, the order of the array key values ​​will remain unchanged

array array_reverse(array array[,boolean preserve_key])

10. Replace array keys and values

array array_flip(array array)

11. Array order sorting, sort_flags parameter is optional, default behavior

SORT_NUMBERIC，按数值排序，对整数或浮点数排序很有用
SORT_REGULAR，按照ASCII值排序
SORT_STRING，按接近人所认识的正确顺序排序
asort函数键值顺序不变
void sort(array array[,int sort_flags])
void asort(array array[,int sort_flags])

12. The array is sorted in reverse order, the sort_flags parameter is optional, and the default behavior is

SORT_NUMBERIC，按数值排序，对整数或浮点数排序很有用
SORT_REGULAR，按照ASCII值排序
SORT_STRING，按接近人所认识的正确顺序排序
arsort函数键值顺序不变
void rsort(array array[,int sort_flags])
void arsort(array array[,int sort_flags])

13. Natural sorting of arrays

void natsort(array array)

14. Case-insensitive natural sorting

void natcasesort(array array)

15. Sort the array by key value

boolean ksort(array array[,int sort_flags])

16. Sort the key-value array in reverse order

boolean krsort(array array[,int sort_flags])

17. Sort according to user-defined order

void usort(array array,callback function_name)

18. Merge the arrays together and return a combined array. The back of array_merge covers the front, array_merge_recursive merges together

array array_merge(array array1[array array2……])//一个以上
array array_merge_recursive(array array1,array array2[,array ……])//两个以上

19. Keys and values ​​form a new array

array array_combine(array key,array value)

20. Returns a part of the array, starting from offset and ending at offset+length

array array_slice(array array, int offset [,int length])

21. Delete all elements starting from offset and ending at offset+length, and return the deleted elements in the form of an array

array array_splice(array, int offset [,int length[,array peplacement]])

22. Find the intersection of arrays, the key value is the key value in the first array

array array_intersect(array array1,array array2[,arrayN……])

23. Find the intersection of the arrays if the key value is equal, and the key value is the key value in the first array

array array_intersect_assoc(array array1,array array2[,arrayN……])

24. Find the difference set of arrays, the first array has a value that is not found in other arrays

array array_diff(array array1,array array2[,arrayN……])

25. Find the difference set of arrays. The first array contains equal key values ​​in values ​​that are not found in other arrays

array array_diffassoc(array array1,array array2[,arrayN……])

26. Returns one or more key values ​​in the array

mixed array_rand(array array[,int num_entries])

27. Shuffle function

void shuffle(array input_array)

28. Sum the values ​​in an array

mixed array_sum(array array);

29. Decompose the array into a multi-dimensional array, which contains size elements

array array_chunk(array array, int size [,boolean preserve_keys])

http://www.bkjia.com/PHPjc/752578.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/752578.htmlTechArticleThe most commonly used data structure in PHP is arrays, which can help us solve a large part of programming problems. In fact, there are many array operations that we don’t need to write ourselves, the system already comes with them...