让我的函数访问外部变量

Question

我外面有一个阵列：

$myArr = array();

我想让我的函数访问它外面的数组，以便它可以为它添加值

function someFuntion(){
    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;
}

如何为函数提供正确的范围？

Answer 1

默认情况下，当您在函数内部时，您无权访问外部变量。

如果您希望函数有权访问外部变量，则必须在函数内声明为global：

function someFuntion(){
    global $myArr;
    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;
}

有关更多信息，请参阅Variable scope。

但请注意使用全局变量不是一个好习惯：这样，你的函数就不再是独立的了。

更好的想法是让你的函数返回结果：

function someFuntion(){
    $myArr = array();       // At first, you have an empty array
    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;      // Put that $myVal into the array
    return $myArr;
}

并调用这样的函数：

$result = someFunction();

您的函数也可以使用参数，甚至处理通过引用传递的参数：

function someFuntion(array & $myArr){
    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;      // Put that $myVal into the array
}

然后，调用这样的函数：

$myArr = array( ... );
someFunction($myArr);  // The function will receive $myArr, and modify it

有了这个：

• 您的函数收到外部数组作为参数
• 可以修改它，因为它是通过引用传递的。
• 这比使用全局变量更好：您的函数是一个单元，与任何外部代码无关。

有关这方面的更多信息，您应该阅读PHP手册的Functions部分，尤其是以下小节：

• Functions arguments
• Returning values

Answer 2

$foo = 42;
$bar = function($x = 0) use ($foo){
    return $x + $foo;
};
var_dump($bar(10)); // int(52)

更新：现在支持箭头功能，但我会让那些使用它更多的人来创建答案

Answer 3

Global $myArr;
$myArr = array();

function someFuntion(){
    global $myArr;

    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;
}

预先警告，通常人们会避免使用全局，因为它有一些缺点。

你可以试试这个

function someFuntion($myArr){
    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;
    return $myArr;
}
$myArr = someFunction($myArr);

这样就可以让你不依赖于Globals。

Answer 4

$myArr = array();

function someFuntion(array $myArr) {
    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;

    return $myArr;
}

$myArr = someFunction($myArr);

Answer 5

实现目标的一种可能不太好的方法是使用全局变量。

您可以通过将global $myArr;添加到函数的开头来实现此目的。 但请注意，在大多数情况下使用全局变量是一个坏主意，可能是可以避免的。

更好的方法是将数组作为参数传递给函数：

function someFuntion($arr){
    $myVal = //some processing here to determine value of $myVal
    $arr[] = $myVal;
    return $arr;
}

$myArr = someFunction($myArr);

Answer 6

两个答案

1。回答问题。

2。简单的改变等于更好的方式！

答案1 - 将Vars数组传递给类中的__construct（），您也可以将构造留空并通过函数传递数组。

<?php

// Create an Array with all needed Sub Arrays Example: 
// Example Sub Array 1
$content_arrays["modals"]= array();
// Example Sub Array 2
$content_arrays["js_custom"] = array();

// Create a Class
class Array_Pushing_Example_1 {

    // Public to access outside of class
    public $content_arrays;

    // Needed in the class only
    private $push_value_1;
    private $push_value_2;
    private $push_value_3;
    private $push_value_4;  
    private $values;
    private $external_values;

    // Primary Contents Array as Parameter in __construct
    public function __construct($content_arrays){

        // Declare it
        $this->content_arrays = $content_arrays;

    }

    // Push Values from in the Array using Public Function
    public function array_push_1(){

        // Values
        $this->push_values_1 = array(1,"2B or not 2B",3,"42",5);
        $this->push_values_2 = array("a","b","c");

        // Loop Values and Push Values to Sub Array
        foreach($this->push_values_1 as $this->values){

            $this->content_arrays["js_custom"][] = $this->values;

        }

        // Loop Values and Push Values to Sub Array
        foreach($this->push_values_2 as $this->values){

            $this->content_arrays["modals"][] = $this->values;

        }

    // Return Primary Array with New Values
    return $this->content_arrays;

    }

    // GET Push Values External to the Class with Public Function
    public function array_push_2($external_values){

        $this->push_values_3 = $external_values["values_1"];
        $this->push_values_4 = $external_values["values_2"];

        // Loop Values and Push Values to Sub Array
        foreach($this->push_values_3 as $this->values){

            $this->content_arrays["js_custom"][] = $this->values;

        }

        // Loop Values and Push Values to Sub Array
        foreach($this->push_values_4 as $this->values){

            $this->content_arrays["modals"][] = $this->values;

        }

    // Return Primary Array with New Values
    return $this->content_arrays;

    }

}

// Start the Class with the Contents Array as a Parameter
$content_arrays = new Array_Pushing_Example_1($content_arrays);

// Push Internal Values to the Arrays
$content_arrays->content_arrays = $content_arrays->array_push_1();

// Push External Values to the Arrays
$external_values = array();
$external_values["values_1"] = array("car","house","bike","glass");
$external_values["values_2"] = array("FOO","foo");
$content_arrays->content_arrays = $content_arrays->array_push_2($external_values);

// The Output
echo "Array Custom Content Results 1";
echo "<br>";
echo "<br>";

echo "Modals - Count: ".count($content_arrays->content_arrays["modals"]);
echo "<br>";
echo "-------------------";
echo "<br>";

// Get Modals Array Results
foreach($content_arrays->content_arrays["modals"] as $modals){

    echo $modals;
    echo "<br>";

}

echo "<br>";
echo "JS Custom - Count: ".count($content_arrays->content_arrays["js_custom"]);
echo "<br>";
echo "-------------------";
echo "<br>";

// Get JS Custom Array Results
foreach($content_arrays->content_arrays["js_custom"] as $js_custom){

    echo $js_custom;
    echo "<br>";


}

echo "<br>";

?>

回答2 - 然而，一个简单的改变会使其符合现代标准。 只需在类中声明您的数组。

<?php

// Create a Class
class Array_Pushing_Example_2 {

    // Public to access outside of class
    public $content_arrays;

    // Needed in the class only
    private $push_value_1;
    private $push_value_2;
    private $push_value_3;
    private $push_value_4;  
    private $values;
    private $external_values;

    // Declare Contents Array and Sub Arrays in __construct
    public function __construct(){

        // Declare them
        $this->content_arrays["modals"] = array();
        $this->content_arrays["js_custom"] = array();

    }

    // Push Values from in the Array using Public Function
    public function array_push_1(){

        // Values
        $this->push_values_1 = array(1,"2B or not 2B",3,"42",5);
        $this->push_values_2 = array("a","b","c");

        // Loop Values and Push Values to Sub Array
        foreach($this->push_values_1 as $this->values){

            $this->content_arrays["js_custom"][] = $this->values;

        }

        // Loop Values and Push Values to Sub Array
        foreach($this->push_values_2 as $this->values){

            $this->content_arrays["modals"][] = $this->values;

        }

    // Return Primary Array with New Values
    return $this->content_arrays;

    }

    // GET Push Values External to the Class with Public Function
    public function array_push_2($external_values){

        $this->push_values_3 = $external_values["values_1"];
        $this->push_values_4 = $external_values["values_2"];

        // Loop Values and Push Values to Sub Array
        foreach($this->push_values_3 as $this->values){

            $this->content_arrays["js_custom"][] = $this->values;

        }

        // Loop Values and Push Values to Sub Array
        foreach($this->push_values_4 as $this->values){

            $this->content_arrays["modals"][] = $this->values;

        }

    // Return Primary Array with New Values
    return $this->content_arrays;

    }

}

// Start the Class without the Contents Array as a Parameter
$content_arrays = new Array_Pushing_Example_2();

// Push Internal Values to the Arrays
$content_arrays->content_arrays = $content_arrays->array_push_1();

// Push External Values to the Arrays
$external_values = array();
$external_values["values_1"] = array("car","house","bike","glass");
$external_values["values_2"] = array("FOO","foo");
$content_arrays->content_arrays = $content_arrays->array_push_2($external_values);

// The Output
echo "Array Custom Content Results 1";
echo "<br>";
echo "<br>";

echo "Modals - Count: ".count($content_arrays->content_arrays["modals"]);
echo "<br>";
echo "-------------------";
echo "<br>";

// Get Modals Array Results
foreach($content_arrays->content_arrays["modals"] as $modals){

    echo $modals;
    echo "<br>";

}

echo "<br>";
echo "JS Custom - Count: ".count($content_arrays->content_arrays["js_custom"]);
echo "<br>";
echo "-------------------";
echo "<br>";

// Get JS Custom Array Results
foreach($content_arrays->content_arrays["js_custom"] as $js_custom){

    echo $js_custom;
    echo "<br>";


}

echo "<br>";

?>

两个选项都输出相同的信息，并允许函数将数据和子数组中的信息推送和检索到代码中的任何位置（假设数据已先被推送）。第二个选项可以更好地控制数据的使用和保护方式。它们可以根据您的需要进行修改，但如果它们用于扩展Controller，则可以在Controller使用的任何类之间共享它们的值。这两种方法都不需要使用Global（s）。

<强>输出：

数组自定义内容结果

模态 - 数量：5

一

B'/ P>

C

FOO

FOO

JS自定义 - 数量：9

1

2B或2B

3

42

5

车

房子

自行车

玻璃