PHP array_filter()函數 (PHP array_filter() Function)
array_filter() function is used to apply a filter on array elements based on the function and returns the array with filtered elements, it accepts an array to be checked and a callback function. The callback function is used to validate the elements in the array.
array_filter()函數用于基于該函數在數組元素上應用過濾器，并返回帶有已過濾元素的數組，它接受要檢查的數組和回調函數。 回調函數用于驗證數組中的元素。
Syntax:
句法：
array_filter(array,callback_function) : array
Here,
這里，
array is the input array in which we have to apply the filter.
數組是我們必須在其中應用過濾器的輸入數組。
callback_function is the function, in which we write the condition to be validated.
callback_function是函數，我們在其中編寫要驗證的條件。
Examples:
例子：
Input:
$arr = array(10, 20, -10, -20, 50, 0);
//here we have to filter the positive numbers
//the callback function to check the positive number is "isPositive()"
Function calling:
$temp = array_filter($arr, "isPositive");
Output:
Array
(
[0] => 10
[1] => 20
[4] => 50
)
So, here 0th , 1st and 4th elements are positive
PHP code 1: Find the positive number from given array of the numbers.
PHP代碼1：從給定的數字數組中找到正數。
<?php
//function to check wheather number is positive or not
function isPositive($val)
{
if($val>0)
return $val;
}
// array
$arr = array(10, 20, -10, -20, 50, 0);
// array with only positive value
$temp = array_filter($arr, "isPositive");
print_r ($temp);
?>
Output
輸出量
Array
(
[0] => 10
[1] => 20
[4] => 50
)
PHP code 2: Find the persons who are eligible for voting from given array of persons
PHP代碼2：從給定的一組人員中找到有資格投票的人員
Here, we also have the "keys" and based on the age key we are checking the voting eligibility.
在這里，我們還有“鍵”，并且根據年齡鍵，我們正在檢查投票資格。
<?php
//function to check wheather person is eligible
//for voting or not?
function isVoter($val)
{
if($val['age']>=18)
return $val;
}
// person's array
$arr = array(
array("name" => "Prem", "age" => 28,"city" => "Gwalior",),
array("name" => "Manju", "age" => 25,"city" => "Gwalior",),
array("name" => "Radib Kar", "age" => 23,"city" => "Chennai",),
array("name" => "Prerana", "age" => 17,"city" => "Gwalior",),
);
// array with voting eligible persons
$temp = array_filter($arr, "isVoter");
print_r ($temp);
?>
Output
輸出量
Array
(
[0] => Array
(
[name] => Prem
[age] => 28
[city] => Gwalior
)
[1] => Array
(
[name] => Manju
[age] => 25
[city] => Gwalior
)
[2] => Array
(
[name] => Radib Kar
[age] => 23
[city] => Chennai
)
)
翻譯自: https://www.includehelp.com/php/array_filter-function-with-example.aspx
