How to pass parameters between php methods

In PHP, passing parameters between functions is a very common thing. Passing parameters allows us to pass data from one function to another and process it.

Before that, let us first understand how functions and their parameters are defined in PHP. In PHP, the function definition is as follows:

function function_name($parameter1, $parameter2, ..., $parameterN) {
  // code to be executed
}

As shown in the above code, the function definition must include the function name and the corresponding parameter list. A parameter list consists of a series of comma-separated parameters, each represented by a dollar sign ($) and the parameter name.

Now let’s look at how to pass parameters between functions.

In PHP, parameters can be passed between functions in different ways, such as by value and by reference.

Pass-by-value method

In PHP, the default method of parameter passing is by-value method. This means that the parameters in the function are copied into a new variable and that copy is used in the function. When the function completes execution and returns, the copy is destroyed.

The following is an example of passing by value:

function multiply($num1, $num2) {
  $result = $num1 * $num2;
  return $result;
}

$a = 10;
$b = 20;
echo multiply($a, $b);

In the above example, we call a function named multiply(), passing two variables to it as parameters. The multiply() function multiplies the two arguments it receives and returns the result. We store the result in a variable and output it using echo.

Pass-by-reference method

Different from the pass-by-value method, the pass-by-reference method allows passing a reference to a parameter between functions rather than a copy of the value. Pass-by-reference allows the original variable to be modified and those changes reflected in code outside of the function call.

The following is an example of passing by reference:

function addNumber(&$num) {
  $num += 5;
}

$a = 10;
addNumber($a);
echo $a;

In the above example, we define a function named addNumber(), which receives a $num parameter of reference type, and increase it by 5. When we call this function, the value of variable $a is passed as a reference type. Therefore, when we modify $num in the function, we are actually modifying the value of the original variable $a.

Finally, we use echo to output the value of variable $a.

In this article, we learned two ways to pass parameters between functions in PHP: passing by value and passing by reference. When we need to pass data between functions, we can use these methods to achieve our needs.

To summarize, when we pass a value, the function receives a copy of the original value. When we pass a reference, the function receives a reference to the original value, and we can modify the value of the original variable inside the function.

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