User defined function in PHP

User defined function in php is quite a common thing. You can create User defined functions in PHP. User defined function is very useful feature in the programming language. User defined function allows you to create your own functions and use them anywhere in your application without worrying about the names of the functions. You can also specify parameters for these User defined functions and even return values as well as null values.

function functionName() {
  code to be executed;
}