php array_intersect 没有得到第一个值

Question

基本上，我正在尝试将 csv 数据导入我的数据库。在将数据插入数据库之前，我想检查数据库是否有该列（来自 csv headers）。

        // read csv from file ex: data.csv
        $reader = \League\Csv\Reader::createFromPath($file);            

        // get first row from csv as headers (email, first_name, last_name etc.)
        $headers = array_filter(array_map(function($value) { return strtolower(trim($value)); }, $reader->fetchOne()));

        // get fields from database (email, first_name, last_name, birthdate etc.)
        $fields = collect($this->fields)->map(function ($field) {
            return strtolower($field->tag);
        })->toArray();


        // want to check which fields has csv
        $availableFields = array_intersect($headers, $fields);

但是当我运行上面的代码时，array_intersect无法正常工作。

输出为：

 $headers : Array ([0] => email [1] => first_name [2] => last_name ) 

 $fields : Array ( [0] => email [1] => first_name [2] => last_name     [3] => telephone     [4] => gender     [5] => birthdate     [6] => country  ) 

 $availableFields :Array ([1] => first_name [2] => last_name )

var_dump 结果是：

$headers : array(3) {
  [0]=>
  string(8) "email"
  [1]=>
  string(10) "first_name"
  [2]=>
  string(9) "last_name"
}
$fields : array(9) {
  [0]=>
  string(5) "email"
  [1]=>
  string(10) "first_name"
  [2]=>
  string(9) "last_name"
  [3]=>
  string(9) "telephone"
  [4]=>
  string(6) "gender"
  [5]=>
  string(9) "birthdate"
  [6]=>
  string(7) "country"
}

Answer 1

trim() function in php cuts off only 6 non-printable characters per default. I think that's your problem because there are more non-printable characters (list of characters).

例如：

<?php

var_dump([trim("EMAIL\x1C")]);

trim() 允许您在第二个参数中指定字符掩码：

<?php 

trim($binary, "\x00..\x1F");

而不是使用 trim()，正则表达式提供了更多的保证：

<?php

// preg_replace('/[\x00-\x1F\x7F]/u', '', $value)
$headers = array_filter(array_map(function($value) { return strtolower(preg_replace('/[\x00-\x1F\x7F]/u', '', $value)); }, $reader->fetchOne()));

php array_intersect 没有得到第一个值

php array_intersect don't get the first value

php

arrays

array-intersect