oop - When would you use the $this keyword in PHP? -

when use $this keyword in php? understand $this refers object created without knowing objects name.

also keyword $this can used within method?

an example great show when can use $this.

a class may contain own constants, variables (called "properties"), , functions (called "methods").

<?php class simpleclass {     // property declaration     public $var = 'a default value';      // method declaration     public function displayvar() {         echo $this->var;     } } ?> 

some examples of $this pseudo-variable:

<?php class {     function foo()     {         if (isset($this)) {             echo '$this defined (';             echo get_class($this);             echo ")\n";         } else {             echo "\$this not defined.\n";         }     } }  class b {     function bar()     {         // note: next line issue warning if e_strict enabled.         a::foo();     } }  $a = new a(); $a->foo();  // note: next line issue warning if e_strict enabled. a::foo(); $b = new b(); $b->bar();  // note: next line issue warning if e_strict enabled. b::bar(); ?> 

the above example output:

• $this defined (a)
• $this not defined.
• $this defined (b)
• $this not defined.