How to cast variable to array in php

In PHP, sometimes you need to cast a variable to an array. In this case, type conversion or type casting can be used. This article will introduce how to cast a variable to an array in PHP.

1. Use (array) for type conversion

PHP allows the use of (array) to force a variable to an array.

Sample code:

$num = 123;
$arr = (array)$num;

Explanation:

In the above code, we define a variable $num and assign it a value of 123. Then use (array) to cast $num to an array type and assign it to the $arr variable.

Note:

• If the original variable is already an array type, (array) will return the original value;
• If the original variable is an object, then (array) An attempt will be made to convert the object to an array (see next section);
• If the original variable is neither an array nor an object, then (array) will create an array with only one element whose value is the value of the original variable .

2. Use toArray() method

If the original variable is an object type, you can use the toArray() method to convert the object to an array. However, the object must be an accessible array object that implements the ArrayAccess interface.

Sample code:

class MyObject implements ArrayAccess {
    private $myArray = array("a" => 1, "b" => 2, "c" => 3);

    // 实现 ArrayAccess 接口
    public function offsetExists($offset) {
        return isset($this->myArray[$offset]);
    }

    public function offsetGet($offset) {
        return $this->myArray[$offset];
    }

    public function offsetSet($offset, $value) {
        $this->myArray[$offset] = $value;
    }

    public function offsetUnset($offset) {
        unset($this->myArray[$offset]);
    }

    // 定义 toArray() 方法
    public function toArray() {
        return $this->myArray;
    }
}

$obj = new MyObject();
$arr = $obj->toArray();

Explanation:

In the above code, we define a MyObject class, which implements the ArrayAccess interface and defines a toArray() Method in which the object is converted to an array and returned.

Then, we create a MyObject object and convert it to an array type using the toArray() method.

Note: If an object does not implement the ArrayAccess interface, it cannot be converted to an array type using the toArray() method.

3. Manually construct an array

You can also manually construct an array and use the value of the original variable as the element of the array.

Sample code:

$name = "Tom";
$age = 25;

// 手动构造数组
$arr = array("name" => $name, "age" => $age);

Explanation:

In the above code, we defined two variables $name and $age, and assigned the values ​​​​to the strings "Tom" and Integer 25.

Then, we use the array() function to manually construct an array $arr. The array contains two elements, which are the values ​​of the $name and $age variables.

Note: The method of manually constructing an array is suitable for situations where key names need to be specified.

Summary

This article introduces three methods of coercing variables into arrays in PHP:

• Use (array) for type conversion
• Use toArray() method
• Manually construct the array

Just choose different methods according to different scenarios. It should be noted that if the original variable is an object type, you need to implement the ArrayAccess interface to convert it to an array type using the toArray() method.

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