Ayuda con json

{
"valor1":"1",
"valor2":"2",
"valor3":"3",
"valor4":[{"valor4.1":"4.1","valor4.2":"4.2","valor4.3":"4.3"},{"valor4.1":"4.1","valor4.2":"4.2","valor4.3":"4.3"}],
"valor5":[{"valor5.1":"5.1","valor5.2":"5.2","valor5.3":"5.3"},{"valor5.1":"5.1","valor5.2":"5.2","valor5.3":"5.3"},{"valor5.1":"5.1","valor5.2":"5.2","valor5.3":"5.3"}],
"valor6":{"valor6.1":"6.1","valor6.2":"6.2"},
"valor7":{"valor7.1":"7.1","valor7.2":"7.2"}
}

				$i = json_decode($html);
				$1 = $i->valor1;
				$2 = $i->valor2;
				$3 = $i->valor3;

$i = json_decode($html);
$_1 = $i->valor1;
$_2 = $i->valor2;
$_3 = $i->valor3;
$_4 = $i->valor4; 
$_5 = $i->valor5; 
$_6 = $i->valor6; 
$_7 = $i->valor7; 

echo '<h3>Valor 5</h3>';
foreach($_5 as $object)
{
	foreach(get_object_vars($object) as $key => $value) echo $key .' = '. $value .'<br />';
}

echo '<h3>Valor 6</h3>';
foreach(get_object_vars($_6) as $key => $value) echo $key .' = '. $value .'<br />';

echo '<h3>Valor 7</h3>';
foreach(get_object_vars($_7) as $key => $value) echo $key .' = '. $value .'<br />';

<?php
$array = json_decode($json, true); //true indica que el resultado debe ser una array asociativo

echo $algo["valor4"][0]["valor4.1"]; //muestra "4.1"
?>