PHP round to integer

Integers stored within floats are always accurate, up to around 2⁵³, which is much more than can be stored in an int anyway. I am worrying over nothing.

What about simply adding 1/2 before casting to an int?

eg:

$int = (int) ($float + 0.5);

This should give a predictable result.

round(), without a precision set always rounds to the nearest whole number. By default, round rounds to zero decimal places.

So:

$int = 8.998988776636;
round($int) //Will always be 9

$int = 8.344473773737377474;
round($int) //will always be 8

So, if your goal is to use this as a key for an array, this should be fine.

You can, of course, use modes and precision to specify exactly how you want round() to behave. See this.

UPDATE

You might actually be more interested in intval:

echo intval(round(4.7)); //returns int 5
echo intval(round(4.3)); // returns int 4

To round floats properly, you can use:

• ceil($number): round up
• round($number, 0): round to the nearest integer
• floor($number): round down

Those functions return float, but from Niet the Dark Absol comment: "Integers stored within floats are always accurate, up to around 2^51, which is much more than can be stored in an int anyway."