PHP Unset() vs Unlink() Function

unset() and unlink() are two different functions in PHP used for different purposes:

1. unset() Function:

• unset() is a language construct in PHP used to unset or destroy a variable or an element of an array.
• When you unset a variable, it removes the variable and its value from memory, making the variable undefined.
• When you unset an element from an array, it removes that specific element from the array, and the array keys may be reindexed if necessary.
• It’s important to note that unset() is not used for deleting files; its primary purpose is to remove variables or array elements.

Syntax of unset():

unset(mixed $variable [, mixed $... ])

Example:

$var1 = "Hello";
$var2 = 42;

unset($var1, $var2);

// $var1 and $var2 are now undefined and no longer accessible.

2. unlink() Function:

• unlink() is a built-in function in PHP used to delete a file from the file system.
• It is specifically used to remove files, and it cannot be used to remove directories or unset variables.
• Be cautious when using unlink() because it permanently deletes the file from the file system, and there is no undo operation.

Syntax of unlink():

bool unlink(string $filename [, resource $context ])

Example:

$file = "example.txt";

if (file_exists($file)) {
    if (unlink($file)) {
        echo "File deleted successfully.";
    } else {
        echo "Failed to delete the file.";
    }
} else {
    echo "File does not exist.";
}

In this example, we use unlink() to delete the file “example.txt” from the file system if it exists. The function returns true on success and false on failure, so we check the return value to determine whether the file was deleted successfully.

To summarize, unset() is used to remove variables or array elements from memory, while unlink() is used to delete files from the file system. They serve different purposes and should be used accordingly based on your specific requirements.