What is the php array passed?

PHP arrays are passed by value, which refers to passing an array from one place to another, either within a function or between different pages or files. PHP arrays can be passed by value or by reference.

The operating environment of this tutorial: windows10 system, php8.1.3 version, DELL G3 computer.

PHP is a popular server-side scripting language widely used for web development. In PHP, arrays are widely used to store and process data. An array is a special type of variable that can store multiple values ​​in a single variable.

The passing of PHP arrays refers to passing an array from one place to another, either within a function or between different pages or files. PHP arrays can be passed by value or by reference.

In PHP, an array is an ordered collection of key-value pairs. Keys are indexes or strings, and values ​​can be any type of data, including scalar values, arrays, and objects. The keys and values ​​of the array are related through the "=>" symbol. The following is an example PHP array:

$fruits = array("apple" => "red", "banana" => "yellow", "orange" => 
"orange");

In the above example, `$fruits` is an associative array containing three elements. Each element consists of a key and a value. The key is the name of the fruit and the value is the color of the corresponding fruit.

Passing by value means passing the entire array as a parameter to a function or assigning the array to another variable. In value transfer, the function or variable receives a copy of the original array, and modifications to the copy will not affect the original array. The example is as follows:

function changeColor($array) {
$array["apple"] = "green";
}
$fruits = array("apple" => "red", "banana" => "yellow", "orange" => 
"orange");
changeColor($fruits);
echo $fruits["apple"]; // 输出: red

In the above example, the `changeColor()` function receives a copy `$array` of the original array `$fruits`, and then modifies the value corresponding to the "apple" key in the copy to "green". However, since a copy is passed, modifications to the copy do not affect the original array, so on output, it is still "red".

Passing by reference refers to passing a reference to an array to a function or variable. In reference passing, the function or variable receives a reference to the original array, and modifications to the reference will affect the original array. The example is as follows:

function changeColor(&$array) {
$array["apple"] = "green";
}
$fruits = array("apple" => "red", "banana" => "yellow", "orange" => 
"orange");
changeColor($fruits);
echo $fruits["apple"]; // 输出: green

In the above example, the `changeColor()` function received the reference `$array` of the original array `$fruits`, and then modified the value corresponding to the "apple" key in the reference to " green". Since it is passed by reference, modifications to the reference will directly affect the original array, so when output, the result is "green".

The passing of PHP arrays can flexibly meet different needs. The operation and modification of arrays can be achieved through value passing or reference passing. When developers use array transfer, they need to choose the appropriate transfer method based on specific needs. .

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