How to process CSV files using PHP? (code example)

In PHP we can use the fgetcsv() function to parse CSV files, which can automatically parse the CSV fields in a given resource. The following article will give you a detailed introduction to how to use PHP to process CSV files. I hope it will be helpful to you. [Video tutorial recommendation: PHP tutorial]

What is a CSV file?

A CSV file is basically just a text file that conforms to a specific format, a plain text file format used to store data, typically used in spreadsheet or database software. In a CSV file, all values ​​are separated by commas (hence, the meaning behind the acronym: comma-separated values), while rows are separated by newlines.

Summary: CSV files consist of commas, data and newlines; newlines separate rows and commas separate values/columns.

An example of a CSV file, name it example.csv:

Ted,USA,21
Lisa,UK,23
Michael,USA,20
Louise,Ireland,30

As you can see: each row is separated by commas; the first column is The person's name, the second column is the person's country, and the last column is the person's age; each person is separated by a newline.

How to process CSV files using PHP?

#php can use the fgetcsv() function to parse CSV files; this function parses a line from the opened file and verifies the CSV field.

The syntax is as follows:

fgetcsv("filename.csv", 1000, ",");

filename.csv: The name of the CSV file.

1000: Indicates the length of the longest line.

",": Indicates the optional delimiter parameter. The default is of course comma (,).

In order to use the fgetcsv() function, we need to first use the fopen() function to open the file for reading, and then use the fclose() function to close the file to end the code. In between, we use a loop to parse each CSV row separately.

Let’s briefly introduce how to deal with it:

1. Use the fopen() function to open the file and read it:

$h = fopen("filename.csv", "r");

Use "r ” mode to open the file and read it; the variable $h will save the processing of data from the file.

2. Use the fgetcsv() function to read the data of the CSV file line by line, and save each line of data separately into an array named $data.

$data = fgetcsv($h, 1000, ",");

In order to read all lines, we need to use a while loop:

while (($data = fgetcsv($h, 1000, ",")) !== FALSE) 
{
  // 读取数据
}

3. The file needs to be closed

fclose($h);

Combine the above 3 steps:

<?php
// 打开文件并阅读
if (($h = fopen("example.csv", "r")) !== FALSE) 
{
  // 将每行数据都转换为本地$data变量并储存
  while (($data = fgetcsv($h, 1000, ",")) !== FALSE) 
  {
   //输出每行数据
    var_dump($data);
  }
  // 关闭文件
  fclose($h);
}
?>

Output:

Code example: Convert CSV file to PHP multidimensional array

The following code generates a multidimensional array ( $the_big_array), each of its items consists of an array converted from a single row in the CSV file.

<?php 
$filename = &#39;example.csv&#39;;
// 用于保存所有数据的多维（嵌套）数组
$the_big_array = []; 
// 打开文件并阅读
if (($h = fopen("{$filename}", "r")) !== FALSE) 
{
  // 文件中的每一行数据都被转换为我们调用的单个数组$data
  // 数组的每个元素以逗号分隔
  while (($data = fgetcsv($h, 1000, ",")) !== FALSE) 
  {
    // 每个单独的数组都被存入到嵌套的数组中
    $the_big_array[] = $data;
  }
  // 关闭文件
  fclose($h);
}
// 以可读格式显示代码
echo "<pre class="brush:php;toolbar:false">";
var_dump($the_big_array);
echo "

"; ?>

Output:

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