static::staticFunctionName()
I know what self::staticFunctionName() and parent::staticFunctionName() are, and how they are different from each other and from $this->functionName .
But what is static::staticFunctionName() ?
It's the keyword used in PHP 5.3+ to invoke late static bindings.
Read all about it in the manual: http://php.net/manual/en/language.oop5.late-static-bindings.php
In summary, static::foo() works like a dynamic self::foo() .
class A {
static function foo() {
// This will be executed.
}
static function bar() {
self::foo();
}
}
class B extends A {
static function foo() {
// This will not be executed.
// The above self::foo() refers to A::foo().
}
}
B::bar();
static solves this problem:
class A {
static function foo() {
// This is overridden in the child class.
}
static function bar() {
static::foo();
}
}
class B extends A {
static function foo() {
// This will be executed.
// static::foo() is bound late.
}
}
B::bar();
static as a keyword for this behavior is kind of confusing, since it's all but. :)
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