PHP OOP about reference
Can one please explain with example what does $obj->$a()->$b mean? I've used PHP OOP quite a long time and have seen in some places this structure and开发者_高级运维 not just this $obj->$a(); In what cases should I use it?
$a = 'someMethod';
$b = 'someProperty';
$obj->$a()->$b;
is equal to:
$obj->someMethod()->someProperty;
Read more about variable variables
$a is the name to a method. Hence, if $a = "myFunc"
, this is equivalent to:
$obj->myFunc()->$b;
$b appears to be a reference to a property. The method appears to return an object, so, if $b = "myProp"
, we can modify this to be:
$obj->myFunc()->myprop;
This is really poor form for understandability.
It means that $a()
returns an object, and that $b
is a member of the object $a()
returns.
This is called method chaining when each method returns the original object, so various methods of the same object can be called without having to repeatedly specify $obj->
before each invocation.
The actual term is Fluent Interface, as stated is returns the original object, heres a full example class
Class Fluent {
public $var1;
public $var2;
function setVar1($value) {
$this->var1 = $value;
return $this;
}
function setVar2($value) {
$this->var2 = $value;
return $this;
}
function getVars() {
echo $this->var1 . $this->var2;
}
}
$fluent = new Fluent();
$fluent->setVar1("Foo")->setVar2("Bar")->getVars();
Which will obviously return "FooBar".
HTH
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