What steps can be taken to troubleshoot a "Fatal error: Call to undefined function" in PHP?

The error "Fatal error: Call to undefined function" in PHP typically occurs when a function is called that has not been defined or included in the code. To troubleshoot this issue, ensure that the function is defined or included in the correct file or location. Check for typos in the function name and verify that the function is being loaded before it is called.

// Example code snippet to troubleshoot "Fatal error: Call to undefined function"
// Ensure that the function is defined or included in the code before calling it
include 'functions.php'; // Include the file containing the function definition

// Call the function after including the file
myFunction(); // Call to the defined function