<?php
$obj = new stdClass;
$obj->{123} = '456'; // defined property but unusable as obj->property; see below.
print_r($obj);
echo 'Via {123}: ' . $obj->{123},"\n";
if (isset($obj->{123})) { echo '123 is set',"\n";}
if (property_exists($obj,123)) echo 'property 123 exists',"\n";
echo $obj->{123}; // Parse error: ...unexpected '123' (T_LNUMBER), expecting identifier (T_STRING) or variable (T_VARIABLE) or '{' or '$'
$obj->{'a123'} = $obj->{123};
print_r($obj);
echo 'Via Property a123: ' . $obj->a123,"\n";
// making a hash out of property a
$obj->a["123"] = $obj->{'123'};
$obj->a["a123"] = $obj->{'a123'};
var_dump($obj);
echo 'Via Property "a" and hashkey "123": ' . $obj->a["123"],"\n";
// contrast:
$obj = (object)array('123' => '456'); // '123' => 123 and identifers must be strings
print_r($obj);
echo $obj->{'123'},"\n"; // so "Undefined property: stdClass::$123"
if (!property_exists($obj,'123')) echo 'property 123 does not exist',"\n";
$obj = new stdClass;
$obj->name = "blabe";
echo "The rain in {$obj->name} ...";