What is the significance of avoiding function names starting with a double underscore in PHP?

Avoiding function names starting with a double underscore in PHP is significant because it is reserved for PHP internal functions and methods. Using double underscores at the beginning of a function name can lead to conflicts with existing or future PHP language constructs, causing unexpected behavior or fatal errors in your code. To solve this issue, simply avoid using double underscores as the prefix for function names in your PHP code.

// Incorrect way to define a function with a double underscore prefix
function __myFunction() {
    // Function implementation
}

// Correct way to define a function without a double underscore prefix
function myFunction() {
    // Function implementation
}