array_map - “传递的参数必须是类型数组，字符串给定”错误

Question

I am not sure why the following does not work. I get the above error (topic):

$array = array (); //something goes in here

function del_space(array $a){
foreach($a as $key => $value){
    preg_replace("/; +/", "", $value); 
    }
}

$no_space = array_map("del_space", $array); 

Answer 1

Your function del_space takes an array as the argument. array_map takes every element of the array (second argument) itself, and sends it to the callback (first argument). So unless if you have an array of arrays, this would not work. Your example should look like this:

$array = ['lblab; la'];

function del_space($a){
    return preg_replace("/; +/", "", $a); 
}

$no_space = array_map("del_space", $array);
print_r($no_space);

Gives output:

Array ( [0] => lblab;la)

If you want to pass an array of arrays, than the input should look like this:

$array = [
     ['blabla; bla'],
     ['blabla2; bla2'],
];

function del_space(array $a){
    foreach($a as $key => $value){
        $a[$key] = preg_replace("/; +/", "", $value); 
    }

    return $a;
}

$no_space = array_map("del_space", $array);
print_r($no_space);

With the output:

Array ( [0] => Array ( [0] => blablabla ) [1] => Array ( [0] => blabla2bla2 ) )