Master PHP’s fwrite(): Write Files Efficiently with Code Examples

In PHP, the fwrite() function is used to write content to a file, providing a simple and flexible way to handle common file‑writing needs.

Syntax of fwrite()

fwrite(file, string, length)

Parameter explanations

file

: required. The file handle returned by fopen(). string: required. The data to write; can be a string, array, or other type. length: optional. Maximum number of bytes to write; defaults to the length of the string.

Example: Writing a simple string

Using fwrite() to write to a file:

<?php
$file = fopen("test.txt", "w"); // open file for writing
if ($file) {
    $content = "Hello, World!"; // content to write
    fwrite($file, $content); // write to file
    fclose($file); // close file
    echo "Write successful!";
} else {
    echo "Unable to open file!";
}
?>

The example opens test.txt in write mode, writes "Hello, World!" and closes the file, outputting a success or error message.

Example: Writing an array

Demonstrating how to write an array by serializing it:

<?php
$file = fopen("data.txt", "w");
if ($file) {
    $data = array("Zhang San", "Li Si", "Wang Wu");
    fwrite($file, serialize($data)); // write serialized array
    fclose($file);
    echo "Write successful!";
} else {
    echo "Unable to open file!";
}
?>

This script creates an array, serializes it with serialize(), writes the result to data.txt, and closes the file.

Overall, fwrite() is a practical function for writing various data types to files; just ensure the file is opened with the correct mode and that the data type matches your needs.