PHP中变量处理的更改

Question

I am unable to understand variable Parsing.
I have gone through this link uniform_variable_syntax but this link is so hard me for understand.

class Test{

    public $var=array('baz'=>'a');

    function a(){

        return 'amazing_class<br/>';
    }
}

 function a(){

    return 'amazing_out_of_class<br/>';
}


$obj=new Test();

$bar='var';
echo "1. ".$obj->$bar['baz']();  //Output amazing_out_of_class

$bar=array('baz'=>'a');
echo "2. ".$obj->{$bar['baz']}(); //Output amazing_class

Now lets look at first case : $obj->$bar['baz']()
($obj->$bar)['baz']() >>> ($obj->var['baz'])() >>> a() >>> amazing_out_of_class

Now i also suppose it $obj->{$bar['baz']}() parsed same as above and expected Notice error : undefined Property a

$obj->{$bar['baz']}() >>> ($obj->a)() >>> ($obj->a) is Notice error : undefined Property a

Notice error : undefined Property a is my assumption according to first case but its output amazing_class

Answer 1

Its pretty simple

$bar='var';
echo "1. ".$obj->$bar['baz']();  //Output amazing_out_of_class

For example $obj->$bar'baz' evaluates as bellow

$obj->$bar['baz']() -> $obj->$var['baz']() -> {$obj->a} () -> a()

Second One also evaluates as a

$obj->{$bar['baz']}() -> $obj->{a}() ( $bar['baz'] as a)

Reference :http://php.net/manual/en/language.variables.php php.net/manual/en/language.types.string.php

Please add, if anything is missing

$bar=array('baz'=>'a');
echo "2. ".$obj->{$bar['baz']}();