How can variables be properly checked for their data type in PHP to avoid errors in function calls?

To properly check variables for their data type in PHP, you can use functions like `is_int()`, `is_string()`, `is_array()`, etc. before making function calls that rely on specific data types. This helps prevent errors that may occur if a variable is not of the expected type.

$var = 42;

if (is_int($var)) {
    // Call functions that expect an integer type
    // For example:
    // myFunctionThatRequiresInt($var);
} else {
    // Handle the case where $var is not an integer
}