What should I do if Chinese characters are not displayed when reading csv files in PHP?

Introduction:

CSV file is a commonly used text file format, and the data contained in it can be easily read and processed by programs. As a powerful back-end programming language, PHP language also provides a series of functions and tools for processing CSV files. However, when there are Chinese characters in the CSV file, some developers will encounter the problem that the Chinese characters are not displayed when using PHP to read the CSV file. This article will introduce in detail the reasons and solutions for Chinese characters not being displayed when reading CSV files.

1. Problem description

When some developers use PHP to read CSV files, they will find that the Chinese characters in it cannot be displayed normally, and garbled or other unrecognizable characters appear. At this time, developers often think that this is a problem with PHP reading the CSV file, but in fact, this problem is caused by the character encoding of the CSV file and the method of reading the CSV file.

2. Chinese character encoding

Before solving the problem, we need to know some knowledge about character encoding. Character encoding refers to a method of converting characters into binary data that can be recognized by computers. In CSV files, character encoding usually uses encodings such as ASCII, UTF-8 and GB2312. Among them, ASCII encoding is a 7-bit binary encoding that can only represent basic English letters and symbols; while UTF-8 is a globally accepted encoding method that can represent almost all characters, including Chinese characters. GB2312 is an encoding method designed for Chinese characters and is used to represent simplified Chinese characters.

When reading CSV files, using different encoding methods may cause Chinese characters to not be displayed properly. Therefore, we need to correctly specify the character encoding of the CSV file and use the same encoding to read the CSV file.

3. Solution

With the above knowledge base, we can solve the problem of Chinese characters not being displayed. Below, three common solutions will be introduced.

1. Specify the character encoding of the CSV file

In PHP, we can use the fopen and fgetcsv functions to read CSV files. Among them, the fopen function is used to open the CSV file, and the fgetcsv function is used to read the CSV data line by line. When opening a CSV file with fopen, you can use "r" mode for reading.

$f = fopen('data.csv', 'r');

Here, "data.csv" is the name of the CSV file to be read. In addition, we can also use the mb_convert_encoding function to convert the encoding of the CSV file to the specified encoding method to ensure that the Chinese characters in the CSV file can be displayed normally.

$csv_arr = array();
while($data = fgetcsv($f)) {
for($i=0; $i< count($data); $i ) {

$csv_arr[] = mb_convert_encoding($data[$i], "UTF-8", "GB2312");

}
}

Here, we convert the encoding of the CSV file to UTF-8 so that the program can read Chinese characters correctly.

2. Use iconv function to convert character encoding

In addition to the mb_convert_encoding function, we can also use the iconv function supported by PHP to convert character encoding. The iconv function can convert characters between different encoding methods to ensure that Chinese characters in CSV files can be displayed normally. Here is an example:

$file = "data.csv";
if (file_exists($file)) {
$fileContent = file_get_contents($file);
$fileContent = iconv("GB2312", "UTF-8//IGNORE", $fileContent);
$csv_arr = str_getcsv($fileContent, "\n");
foreach($csv_arr as &$row) {

$row = str_getcsv($row, ",");
array_walk($row, function(&$cell) {
  $cell = mb_convert_encoding($cell, "UTF-8", "GB2312");
});

}
}

Here, we first use the file_get_contents function to read the CSV file content, and then use the iconv function to convert the encoding from GB2312 to UTF-8. Then, use the str_getcsv function to convert the file content into a two-dimensional array to read the data line by line. Finally, we use the array_walk function to convert each element (i.e., cell) in the two-dimensional array to UTF-8 encoding.

3. Using CSV reading tool classes

Finally, we can also use some CSV reading tool classes to read CSV files. These utility classes usually provide convenient interfaces that can flexibly handle various situations, including character encoding issues. Here is an example:

require_once 'CsvReader.php';

$csvReader = new CsvReader('data.csv', 'r', 'GB2312');

while($row = $csvReader->getRow()) {
var_dump($row);
}

Here, we introduce a file named "CsvReader.php" Tool class to read CSV files by creating a CsvReader object. We can specify the path, reading mode and file encoding method of the CSV file during the process of creating a CsvReader object. In this way, when reading CSV files, the problem of Chinese characters not being displayed is solved.

4. Conclusion

It is a common problem that Chinese characters are not displayed in CSV files. When using PHP to read CSV files, we need to have some basic understanding of character encoding, and Use the right methods and tools to solve the problem. This article introduces three solutions, which are to specify the character encoding of the CSV file, use the iconv function to convert the character encoding, and use the CSV reading tool class to read the CSV file. Hope it can help readers in need.

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