<?php
    if($_FILES){
        var_dump(file($_FILES['file']['tmp_name'], FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES));
    }
?>
?
<html>
    <body>
        <form method="post" enctype="multipart/form-data">
            <input type="file" name="file" />
            <button>upload</button>
        </form>
    </body>
</html>

當(dāng)我使用上面的代碼上傳文件時(shí)，輸出以下數(shù)據(jù)：

如圖所示，每個(gè)字符串中都有逗號(hào)，每個(gè)逗號(hào)將一條信息與另一條信息隔開(kāi)。

使用 array_map() 函數(shù)，并且 str_getcsv() 作為回調(diào)函數(shù)，該回調(diào)將解析每個(gè)具有逗號(hào)的字符串并將它們分隔在一個(gè)數(shù)組中。

if($_FILES){
    //loop through the csv file into an array
    $theCSV = array_map('str_getcsv', file($_FILES['file']['tmp_name'], FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES));
    //dump result
    var_dump($theCSV);
}

輸出如下：

輸出的數(shù)據(jù)看起來(lái)比之前要好得多，我們將列標(biāo)題（全名、QQ、電子郵件）作為該數(shù)組的第一個(gè)元素。

我們使用 array_walk() 函數(shù)遍歷此數(shù)組，然后提供一個(gè)回調(diào)函數(shù)，它將列標(biāo)題（全名、QQ、電子郵件）和每個(gè) CSV 數(shù)據(jù)組合為一個(gè)新數(shù)組。

if($_FILES){
    //loop through the csv file into an array
    $theCSV = array_map('str_getcsv', file($_FILES['file']['tmp_name'], FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES));
    /*Walk through the array and combine the headers which is the first element of our csv array with the rest of the csv data*/
    array_walk($theCSV, function(&$ary) use($theCSV) {
        $ary = array_combine($theCSV[0], $ary);
    });
    //dump result
    var_dump($theCSV);
}
?>

注意，在上面的回調(diào)函數(shù)中，我使用了變量& 運(yùn)算符將 $ary 通過(guò)引用傳遞給函數(shù)，這使的我們可以修改原始數(shù)組。當(dāng)我們運(yùn)行上面的代碼時(shí)，這就是我們的 CSV 數(shù)組現(xiàn)在的樣子：

注意這里有個(gè)問(wèn)題：這個(gè)新數(shù)組的第一個(gè)元素是表頭，因?yàn)槲覀冎白屗c CSV 數(shù)組的其他數(shù)組組裝在了一起。可以使用 array_shift() 來(lái)解決這個(gè)問(wèn)題。

if($_FILES){
    //loop through the csv file into an array
    $theCSV = array_map('str_getcsv', file($_FILES['file']['tmp_name'], FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES));
    /*Walk through the array and combine the headers which is the first element of our csv array with the rest of the csv data*/
    array_walk($theCSV, function(&$ary) use($theCSV) {
        $ary = array_combine($theCSV[0], $ary);
    });
    //remove column headers which is the first element
    array_shift($theCSV);
    //dump result
    var_dump($theCSV);
}

這就是我們最終的 CSV 數(shù)組的樣子

將上面的代碼封裝成一個(gè)函數(shù)，如下：

function readCSV($file){
    if(empty($file) || !file_exists($file)) return;
    //store the column headers
    $headers = null;
    $theCSV = array_map('str_getcsv', file($file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES));
    /*Walk through the array and combine the headers which is the first element of our csv array with the rest of the csv data*/
    array_walk($theCSV, function(&$ary) use($theCSV, &$headers) {
            $ary = array_combine($theCSV[0], $ary);
            //store the headers
            $headers = $theCSV[0];
    });
    //remove column headers which is the first element of our csv array
    array_shift($theCSV);
    //return data
    return array(
        "headers" => $headers,
        "data" => $theCSV
    );
}

3. 將數(shù)據(jù)寫(xiě)入 CSV 文件

將數(shù)據(jù)寫(xiě)入 CSV 文件，其邏輯是使用 fopen() 函數(shù)以附加模式打開(kāi) CSV 文件，然后用 fputcsv() 解析我們要寫(xiě)入 CSV 文件的數(shù)據(jù)，然后此方法將這些數(shù)據(jù)寫(xiě)入文件流當(dāng)中。

if($_SERVER['REQUEST_METHOD'] == "POST"){
    $file = "./my_csv_file.csv";
    //loop through the csv file into an array
    $csvData = readCSV($file);
    //create array to store the new data
    $newData = [];
    //loop through headers and then add values as a new array
    foreach($csvData['headers'] as $index => $key){
        if($key == 'Full Name'){
            $newData[$key] = $_POST['full_name'];
        }elseif($key == 'Email'){
            $newData[$key] = $_POST['email'];
        }elseif($key == 'Phone'){
            $newData[$key] = $_POST['phone'];
        }else{
            $newData[$key] = '';
        }
    }
    var_dump($newData);
}

如圖所示就是我們將寫(xiě)入到 CSV 文件的數(shù)組的數(shù)據(jù)

在我們將這些數(shù)據(jù)寫(xiě)入到 CSV 文件之前，我們必須去掉 key，我們可以使用 array_values() 函數(shù)

if($_SERVER['REQUEST_METHOD'] == "POST"){
    $file = "./my_csv_file.csv";
    //loop through the csv file into an array
    $csvData = readCSV($file);
    //create array to store the new data
    $newData = [];
    //loop through headers and then add values as a new array
    foreach($csvData['headers'] as $index => $key){
        if($key == 'Full Name'){
            $newData[$key] = $_POST['full_name'];
        }elseif($key == 'Email'){
            $newData[$key] = $_POST['email'];
        }elseif($key == 'Phone'){
            $newData[$key] = $_POST['phone'];
        }else{
            $newData[$key] = '';
        }
    }
    //open the csv file as in append mode
    $fp = fopen($file, 'a+');
    //remove keys from new data
    $newData = array_values($newData);
    //append data to csv file
    fputcsv($f, $newData);
    //close the resource
    fclose($fp);
}

不出意外的話，數(shù)據(jù)就會(huì)成功寫(xiě)入到 CSV 文件當(dāng)中去了。