Call to Undefined Function Error is very common in WordPress, so we thought to post that provides a six-step solution to tackle it. Watch the video solution to Call to Undefined Function Error in WordPress.
First, check for typos: Verify that the function name in your code is spelt correctly and matches the function name you intend to use. If there is a typo in the function name, PHP will not be able to find the function and will throw the “Call to undefined function” error.
The second is to check for proper function declaration: Make sure the function has been defined before it is called. The function must either be declared in the same file or in a file that is included using include or require statements.
The third is to check for the correct namespace: If the function is defined in a namespace, you need to ensure that you call the function from the correct one. You can add a use statement to import the namespace or prefix the function call with the namespace.
The Forth step is to check for required extensions: If the function requires a PHP extension that is not installed or enabled on the server, you need to install or enable the extension. You can check the PHP manual for the extension requirements and installation instructions.
The Fifth is to restart your server: Sometimes, changes to PHP files or settings may not take effect until the server is restarted. Restarting the server can help resolve the error.
The sixth step is to enable error reporting: Enabling error reporting can help you identify the root cause of the error. You can use your PHP configuration file’s error_reporting and display_errors directives to enable error reporting.
By following any or all these steps, you should be able to identify and resolve the “Call to undefined function” error in your PHP code.