PHP isset multiple

isset() is a built-in function in PHP used to check if a variable or array has been set and is not NULL. However, when dealing with multiple variables or arrays, using isset() on each one may become tedious and repetitive. That's where isset() multiple comes in handy.

Syntax

The syntax for isset() multiple is as follows:

isset(variable1, variable2, ..., variableN)

Where variable1, variable2, etc. are the variables or arrays to check.

Usage

The isset() multiple function returns true if all the variables or arrays are set and are not NULL, and false otherwise.

$name = "John Doe";
$age = 30;
$address = null;

if (isset($name, $age, $address)) {
    echo "All variables are set.";
} else {
    echo "At least one variable is not set.";
}

In the above example, the output will be "At least one variable is not set." since $address is set to null.

Conclusion

Using isset() multiple can simplify your code and make it more efficient when dealing with multiple variables and arrays. It's important to note that using isset() on an undefined variable will result in a warning, so be sure to define all your variables before using isset().