Floating point to integer?

Haris · 01-28-2008, 06:13 PM

For example, if the value of a integer called number is 4856756.55, it should be converted to 4856757. I thought there was a default function by PHP for that but I couldn't find any function. Type juggling doesn't work!!! ARGH!!!

Alan @ CIT · 01-28-2008, 06:21 PM

When converting from a float to an int, PHP just strips the decimal point and everything after it. For example:

PHP Code:


			
<?php



echo (int) 4856756.55;



// echo's 4856756

Take a look at my article on Variables for more info: TalkPHP - Variables for Beginners

For more precise numbers, you'll need to use the BCMath extension in PHP: PHP: BC math - Manual

Alan

RobertK · 01-28-2008, 06:28 PM

Err... round() works too. You can even specify the precision.

PHP Code:


			
$float = 4856756.55;

echo round($float);

ReSpawN · 01-28-2008, 06:35 PM

My thought exactly. You can also simply explode on the dot and then print the $float[1]...

Alan @ CIT · 01-28-2008, 06:37 PM

I think my memory is going, using round() didn't even occur to me, was just thinking of typecasting. Must be getting old

Alan.

ReSpawN · 01-28-2008, 06:43 PM

Quote:

Originally Posted by Alan @ CIT

I think my memory is going, using round() didn't even occur to me, was just thinking of typecasting. Must be getting old

Alan.

Let me scare you in that case... ever heard of ceil()?

Wildhoney · 01-28-2008, 07:41 PM

...And floor() !

Alan @ CIT · 01-28-2008, 07:50 PM

Doesn't intval() just do the same as typecasting to int and always round down?

Alan

ReSpawN · 01-28-2008, 07:55 PM

Correct.

PHP Code:


			
$rNumber1 = 10;
$rNumber2 = 13.37;

intval($rNumber1); // Returns 10
intval($rNumber2); // Returns 13

It also works with large -e numbers and negative values.

Code:

(like 26.98 - 13 = -13.98 => -13)

xenon · 01-28-2008, 08:32 PM

intval doesn't round anything. it just returns the integer part of the number. number_format rounds the number automatically (depending on the decimal precision).

PHP Code:


			
echo intval(13.397); // 13
echo intval(15.99); // 15

echo number_format(15.56, 0, '', ''); // 16
echo number_format(12.21, 0, '', ''); // 12

RobertK · 01-28-2008, 08:37 PM

Actually, that isn't rounding down is -13.98 yields 13, that's just dropping the decimal value. -13.98 rounds down to -14, not -13. Technically that should be a call to floor(), but the results are disparate.