Reffer [this link](http://php.net/manual/en/language.operators.comparison.php).

I know operand with string type translate to number, and then usual math

But see these sample codes:

```
echo intval(1e1);       // 10
var_dump("1e1" == 10);  // true, and it's ok

echo intval(0x1A);      // 26
var_dump("0x1A" == 26); // true, and it's ok

echo intval(042);       // 34
var_dump("042" == 34);  // fasle, Why ?!!!

```

Why last code return false.