在类中初始化静态curl

So I have a class for curl myCurl and I would like to use it for my 2 other classes but in those classes I want myCurl to only have one instance / be static so all objects of those other classes will use the same curl object.

class mycurl { 
   ...
}

And the class that I want to have just one instance of MyCurl

class Company{
private static $curl=new Mycurl();
...
}

This doesn't work syntax error, unexpected 'new' (T_NEW)

You can't initialize class instances in class body in PHP.

To make your example work, you'd have to do something like this:

class Company {
    private static $curl;

    public function __construct() {
        if (null === static::$curl) {
            static::$curl = new Mycurl();
        }
    }
}

Or, maybe a bit nicer way would be:

class Company {
    private static $curl;

    private static function curl() {
        if (null === static::$curl) {
            static::$curl = new Mycurl();
        }
        return static::$curl;
    }
}

This way, it won't be initialized until you actually need it.

You should do it like this:

class Company{
    public function getMycurlInstance()
    {
        static $mycurl;

        if ($mycurl === null) {
            $mysql = new Mycurl();
        }

        return $mycurl;
    }
}

From your comment,

I would want to have a separate object of curl in different class so basically 1 class 1 curl object.

Suppose you have three classes: MyCurl, Class1 and Class2, and you want to use only one instance of MyCurl in Class1 class and one instance of MyCurl in Class2 class, the solution would be like this:

class MyCurl { 

    private static $curlInstances = array( 'Class1' => null, 'Class2' => null);

    private function __construct(){}

    public static function getInstance($class){
        if(in_array($class, array_keys(self::$curlInstances))){
            if(self::$curlInstances[$class] == null){
                self::$curlInstances[$class] = new MyCurl();
            }
            return self::$curlInstances[$class];
        }else{
            return false;
        }
    }

    // your code
}

class Class1{
    private static $curlInstance;

    public static function getCurlInstance() {
        if(!isset(self::$curlInstance)){
            self::$curlInstance = MyCurl::getInstance(get_class());
        }
        return self::$curlInstance;
    }

    // your code
}

class Class2{
    private static $curlInstance;

    public static function getCurlInstance() {
        if(!isset(self::$curlInstance)){
            self::$curlInstance = MyCurl::getInstance(get_class());
        }
        return self::$curlInstance;
    }

    // your code
}

The explanation is given below:

In MyCurl class:

• Create a private static class array $curlInstances. This array will be used to check whether an object has been created for the particular class or not.
• Make its constructor method private. It prevents objects from being created from being created from outside of the class.
• Create a static class method getInstance(). It first checks whether this method has been called from either Class1 or Class2 class or not. If so then it checks whether an instance has been created for the particular class or not. If no object has been created then a new object will be created, otherwise the old object will be returned by the method.

Both Class1 and Class2 class are quite same. In these classes:

• Create a private static class variable $curlInstance to hold the instance of MyCurl class.
• Create a static class method getCurlInstance() to get the instance of MyCurl class using Singleton pattern.

To get unique MyCurl instances for these individual classes, do this:

$class1CurlInstance1 = Class1::getCurlInstance(); // returns only one instance of MyCurl class
$class2CurlInstance1 = Class2::getCurlInstance(); // returns only one instance of MyCurl class

And again, just for the sake of debugging, do this:

// Both $class1CurlInstance2 and $class2CurlInstance2 will have the same old unique MyCurl instances
$class1CurlInstance2 = Class1::getCurlInstance();
$class2CurlInstance2 = Class2::getCurlInstance();