How to pass in an array parameter in php

In PHP, passing parameters is a very important operation. In a function or method, passing in parameters allows you to pass data and information that needs to be processed so that they can be processed further. When it comes to arrays, PHP provides corresponding ways to pass array parameters efficiently.

One-dimensional array passing

When you need to pass a one-dimensional array as a parameter, you can use the function's parameters to pass the array. Here is a simple example:

function showArray($arr) {
   foreach($arr as $value) {
      echo $value . "<br>";
   }
}

$myArray = array("apple", "orange", "banana");
showArray($myArray);

In this example, we create a function called showArray() that accepts a parameter $arr. When we call this function, we pass an array array("apple", "orange", "banana"). Then, in the function, we use the foreach loop to iterate through the array to print each value.

Multidimensional array passing

PHP allows you to pass multidimensional arrays by passing the array to a function or method. Here is a simple example:

function showMultiArray($arr) {
   foreach($arr as $value) {
      if(is_array($value)) {
         showMultiArray($value);
      } else {
         echo $value . "<br>";
      }
   }
}

$myArray = array( "fruit" => array("apple", "orange", "banana"), "vegetable" => array("carrot", "pepper", "onion") );
showMultiArray($myArray);

In this example, we create a function called showMultiArray() that accepts a multidimensional array $arr. When we call this function, we pass a multidimensional array containing a "fruit" array and a "vegetable" array. We use foreach to loop through this multidimensional array and check if each value is an array. If it is an array, the showMultiArray() function is called recursively to iterate over the children of the array. Otherwise, we print out the value.

Passing arrays via the & symbol

By default, PHP copies arrays when passing them to functions. This means that modifying the array inside the function does not affect the original array. But sometimes, you may need to modify the original array inside the function. To do this, you can pass an array by reference. You can pass a variable of an array before a function parameter using the & notation to pass its reference to the function. This means that when the array is modified inside the function, the original array is affected. Here is a simple example:

function addValues(&$arr) {
   $arr[] = "cat";
}

$myArray = array("dog", "fish");
addValues($myArray);
print_r($myArray);

In this example we create a function called addValues() and pass it # using a & symbolic reference ##$arr Array. When we call this function and pass $myArray to it, it will add a new item "cat" to the original array. In the print_r() function, we print out the contents of the original array, showing the newly added "cat".

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