php数组array_filter

 

<?php

$arr = [
'a' => 'aa',
'b' => 0,
'c' => '',
];
//直接用默认过滤函数
print_r(array_filter($arr));

//自定义过滤函数
function test ($var) {
if ($var !== '' && $var != null) {//注意 $var != null
return 1;
}
return 0;
}
$res = array_filter($arr,'test');
print_r($res);

//传入闭包函数
$res = array_filter($arr, function ($var) {//注意 $var !==  null
if ($var !== '' && $var !== null) {
return true;
}
return false;
}
);
print_r($res);

//传入类的过滤函数
class ClsMy{
public function test ($var) {
if ($var !== '' && $var !== null) {
return 4;
}
return false;
}
}

$cls = new ClsMy();

$res = array_filter($arr,[$cls,'test']);//注意[$cls,'test']

print_r($res);


?>

输出

Array
(
[a] => aa
)

Array
(
[a] => aa
)

Array
(
[a] => aa
[b] => 0
)
Array
(
[a] => aa
[b] => 0
)