User defined functions

PHP user-defined functions are blocks of code written by a programmer that can be reused multiple times throughout a PHP script. These functions can be defined by the programmer to perform specific tasks or calculations and can take input parameters and return values.

By creating user-defined functions, programmers can modularize their code, making it easier to read, maintain, and debug. Functions can be called from any part of the code where they are defined, thus saving time and effort in writing repetitive code. To create a user-defined function in PHP, you need to define the function using the function keyword, give it a name, and specify the input parameters and return values (if any). Once defined, the function can be called by its name anywhere in the script where it is needed.