2019 - 02 - 20

array_change_key_case()

array_change_key_case(array $arr, [, int $case = CASE_LOWER]) : array

说明：将所有键名改为全大写或者小写

$arr = [    'name' => '张三',    'Age' => 18,    'gender' => '男',];// case upperprint_r(array_change_key_case($arr, CASE_UPPER));// outputArray(    [NAME] => 张三    [AGE] => 18    [GENDER] => 男)

array_chunk()

array_chunk ( array $array , int $size [, bool $preserve_keys = false ] ) : array

说明：将一个数组分割成多个数组

$arr = [    'name' => '张三',    'Age' => 18,    'gender' => '男',];print_r(array_chunk($arr, 2));// outputArray(    [0] => Array        (            [0] => 张三            [1] => 18        )    [1] => Array        (            [0] => 男        ))

array_column()

array_column ( array $input , mixed $column_key [, mixed $index_key = null ] ) : array

说明：返回数组中指定的一列

$arr = [    0 => [        'name' => 'LeiJian',        'age' => 18,        'gender' => '男',    ],    1 => [        'name' => 'ZhangSan',        'age' => 19,        'gender' => '男',    ],    2 => [        'name' => 'LiSi',        'age' => 20,        'gender' => '女',    ],];print_r(array_column($arr, NULL, 'name'));// outputArray(    [LeiJian] => Array        (            [name] => LeiJian            [age] => 18            [gender] => 男        )    [ZhangSan] => Array        (            [name] => ZhangSan            [age] => 19            [gender] => 男        )    [LiSi] => Array        (            [name] => LiSi            [age] => 20            [gender] => 女        ))

array_combine()

array_combine ( array $keys , array $values ) : array

说明：将一个数组作键值，另一个数组作值产生一个新的数组

$a = [1, 2, 3];$b = ['a', 'b', 'c'];print_r(array_combine($a, $b));// outputArray(    [1] => a    [2] => b    [3] => c)

array_count_values()

array_count_values ( array $array ) : array

说明：数组中的键是 array 中的值，数组中的值是 array 的值出现的次数

$arr = [1, 'hello', 1, 'world', 'world'];print_r(array_count_values($arr));// outputArray(    [1] => 2    [hello] => 1    [world] => 2)

2019 - 02 - 21

array_diff_key()

array_diff_key ( array $array1 , array $array2 [, array $... ] ) : array

使用键名（key）比较数组的差集

$arr1 = ['first' => 2, 'third' => 3, 'fourth' => 4];$arr2 = ['first' => 1, 'second' => 2, 'third' => 3];print_r(array_diff_key($arr1, $arr2));// outputArray(    [fourth] => 4)

array_diff_uassoc()

array_diff_uassoc ( array $array1 , array $array2 [, array $... ], callable $key_compare_func ) : array

说明：使用回调函数做索引检查数组差集

$arr1 = ['first' => 2, 'third' => 3, 'fourth' => 4];$arr2 = ['first' => 1, 'second' => 2, 'third' => 3];print_r(array_diff_uassoc($arr1, $arr2, function($a, $b){    if ($a === $b) {        return 0;    }        return ($a > $b) ? 1 : -1;}));// outputArray(    [first] => 2    [fourth] => 4)

array_diff()

`array_diff ( array $array1 , array $array2 [, array $... ] ) : array

`说明：比较数组间的差集（array1 比较数组，array2 被比较）

$arr1 = [1, 2, 3, 4, 6];$arr2 = [2, 3, 4, 5];print_r(array_diff($arr1, $arr2));// outputArray(    [0] => 1    [4] => 6)

array_fill_keys()

array_fill_keys ( array $keys , mixed $value ) : array

说明：使用指定键值（数组）和值进行填充数组

$arr1 = [1, 2, 3, 4, 6];print_r(array_fill_keys($arr1, 'HaHaHa~'));// outputArray(    [1] => HaHaHa~    [2] => HaHaHa~    [3] => HaHaHa~    [4] => HaHaHa~    [6] => HaHaHa~)

array_fill()

`array_fill ( int $start_index , int $num , mixed $value ) : array

`说明：用给定的值进行填充数组，start_index索引开始位置，若为负值，则从 0 开始，num 为填充数量

print_r(array_fill(2, 3, 'HaHaHa~'));// outputArray(    [2] => HaHaHa~    [3] => HaHaHa~    [4] => HaHaHa~)

array_filter()

array_filter ( array $array [, callable $callback [, int $flag = 0 ]] ) : array

说明：用回调函数过滤数组中的值（flag 决定 callback接收的参数）

$arr1 = [1, 2, 3, 4, 6];print_r(array_filter($arr1, function($value){    if ($value > 2) {        return $value;    }}));// outputArray(    [2] => 3    [3] => 4    [4] => 6)