How to create a function in PHP?

To create a function in PHP, you can use the function keyword followed by the name of the function, a list of arguments in parentheses, and a block of code in curly braces.

Here is an example of a simple function in PHP that takes two arguments and returns their sum:

function add($x, $y) {
  return $x + $y;
}

$result = add(1, 2);
echo $result; // Outputs: 3

In this example, the add() function takes two arguments $x and $y, and returns their sum using the return statement. The function is then called with the arguments 1 and 2, and the result is assigned to the $result variable.

You can also specify default values for function arguments by using the = operator in the argument list. For example:

function add($x, $y = 0) {
  return $x + $y;
}

$result = add(1);
echo $result; // Outputs: 1

In this example, the add() function takes two arguments $x and $y, but the $y argument has a default value of 0. If the add() function is called with only one argument, the default value of 0 will be used for the $y argument.