如何在PHP中修剪数组中的空格

Question

I'm trying to parse a CSV file and as part of it I would like to remove leading/trailing whitespace from all of my cells. Since it's a CSV file it's formatted like a 2D array. Initially I tried:

foreach($csv as $row){
    foreach($row as $cell){
        $cell = trim($cell);
    }
}

However the result was untrimmed.

Next I tried using array_map as suggested here.

$csv = array_map('trim', $csv);

This gave me back an array of empty rows. So I also tried

foreach($csv as $row){
    $row = array_map('trim', $row);
}

Which like my first attempt didn't change anything.

Here's the CSV data I'm using as my input:

First Name,Last Name,Contact Method,Phone, Email John,Doe,Email,1-XXX-XXX-XXXX, [e-mail] Jane,Doe,Phone Call,1-XXX-XXX-XXXX,[e-mail]

In particular I was trying to get my script to trim the leading space in the last cell of the first row (" Email" => "Email").

Answer 1

You are not modifying the original array when you do the trim. You should get the values by reference in the foreach loop.

foreach($csv as &$row){
    foreach($row as &$cell){
        $cell = trim($cell);
    }
}

From the documentation:

In order to be able to directly modify array elements within the loop precede $value with &. In that case the value will be assigned by reference.