How to get whole and decimal part of a number?
PhpMathPhp Problem Overview
Given, say, 1.25 - how do I get "1" and ."25" parts of this number?
I need to check if the decimal part is .0, .25, .5, or .75.
Php Solutions
Solution 1 - Php
$n = 1.25;
$whole = floor($n); // 1
$fraction = $n - $whole; // .25
Then compare against 1/4, 1/2, 3/4, etc.
In cases of negative numbers, use this:
function NumberBreakdown($number, $returnUnsigned = false)
{
$negative = 1;
if ($number < 0)
{
$negative = -1;
$number *= -1;
}
if ($returnUnsigned){
return array(
floor($number),
($number - floor($number))
);
}
return array(
floor($number) * $negative,
($number - floor($number)) * $negative
);
}
The $returnUnsigned stops it from making -1.25 in to -1 & -0.25
Solution 2 - Php
This code will split it up for you:
list($whole, $decimal) = explode('.', $your_number);
where $whole is the whole number and $decimal will have the digits after the decimal point.
Solution 3 - Php
The floor() method doesn't work for negative numbers. This works every time:
$num = 5.7;
$whole = (int) $num; // 5
$frac = $num - $whole; // .7
...also works for negatives (same code, different number):
$num = -5.7;
$whole = (int) $num; // -5
$frac = $num - $whole; // -.7
Solution 4 - Php
Just to be different :)
list($whole, $decimal) = sscanf(1.5, '%d.%d');
As an added benefit, it will only split where both sides consist of digits.
Solution 5 - Php
a short way (use floor and fmod)
$var = "1.25";
$whole = floor($var); // 1
$decimal = fmod($var, 1); //0.25
then compare $decimal to 0, .25, .5, or .75
Solution 6 - Php
Cast it as an int and subtract
$integer = (int)$your_number;
$decimal = $your_number - $integer;
Or just to get the decimal for comparison
$decimal = $your_number - (int)$your_number
Solution 7 - Php
There's a fmod function too, that can be used : fmod($my_var, 1) will return the same result, but sometime with a small round error.
Solution 8 - Php
PHP 5.4+
$n = 12.343;
intval($n); // 12
explode('.', number_format($n, 1))[1]; // 3
explode('.', number_format($n, 2))[1]; // 34
explode('.', number_format($n, 3))[1]; // 343
explode('.', number_format($n, 4))[1]; // 3430
Solution 9 - Php
This is the way which I use:
$float = 4.3;
$dec = ltrim(($float - floor($float)),"0."); // result .3
Solution 10 - Php
Brad Christie's method is essentially correct but it can be written more concisely.
function extractFraction ($value)
{
$fraction = $value - floor ($value);
if ($value < 0)
{
$fraction *= -1;
}
return $fraction;
}
This is equivalent to his method but shorter and hopefully easier to understand as a result.
Solution 11 - Php
$x = 1.24
$result = $x - floor($x);
echo $result; // .24
Solution 12 - Php
If you can count on it always having 2 decimal places, you can just use a string operation:
$decimal = 1.25;
substr($decimal,-2); // returns "25" as a string
No idea of performance but for my simple case this was much better...
Solution 13 - Php
Just a new simple solution, for those of you who want to get the Integer part and Decimal part splitted as two integer separated values:
5.25 -> Int part: 5; Decimal part: 25
$num = 5.25;
$int_part = intval($num);
$dec_part = $num * 100 % 100;
This way is not involving string based functions, and is preventing accuracy problems which may arise in other math operations (such as having 0.49999999999999 instead of 0.5).
Haven't tested thoroughly with extreme values, but it works fine for me for price calculations.
But, watch out! Now from -5.25 you get: Integer part: -5; Decimal part: -25
In case you want to get always positive numbers, simply add abs() before the calculations:
$num = -5.25;
$num = abs($num);
$int_part = intval($num);
$dec_part = $num * 100 % 100;
Finally, bonus snippet for printing prices with 2 decimals:
$message = sprintf("Your price: %d.%02d Eur", $int_part, $dec_part);
...so that you avoid getting 5.5 instead of 5.05. ;)
Solution 14 - Php
To prevent the extra float decimal (i.e. 50.85 - 50 give 0.850000000852), in my case I just need 2 decimals for money cents.
$n = 50.85;
$whole = intval($n);
$fraction = $n * 100 % 100;
Solution 15 - Php
I was having a hard time finding a way to actually separate the dollar amount and the amount after the decimal. I think I figured it out mostly and thought to share if any of yall were having trouble
So basically...
if price is 1234.44... whole would be 1234 and decimal would be 44 or
if price is 1234.01... whole would be 1234 and decimal would be 01 or
if price is 1234.10... whole would be 1234 and decimal would be 10
and so forth
$price = 1234.44;
$whole = intval($price); // 1234
$decimal1 = $price - $whole; // 0.44000000000005 uh oh! that's why it needs... (see next line)
$decimal2 = round($decimal1, 2); // 0.44 this will round off the excess numbers
$decimal = substr($decimal2, 2); // 44 this removed the first 2 characters
if ($decimal == 1) { $decimal = 10; } // Michel's warning is correct...
if ($decimal == 2) { $decimal = 20; } // if the price is 1234.10... the decimal will be 1...
if ($decimal == 3) { $decimal = 30; } // so make sure to add these rules too
if ($decimal == 4) { $decimal = 40; }
if ($decimal == 5) { $decimal = 50; }
if ($decimal == 6) { $decimal = 60; }
if ($decimal == 7) { $decimal = 70; }
if ($decimal == 8) { $decimal = 80; }
if ($decimal == 9) { $decimal = 90; }
echo 'The dollar amount is ' . $whole . ' and the decimal amount is ' . $decimal;
Solution 16 - Php
Try it this way... it's easier like this
$var = "0.98";
$decimal = strrchr($var,".");
$whole_no = $var-$decimal;
echo $whole_no;
echo str_replace(".", "", $decimal);
Solution 17 - Php
You could also use something like this:
preg_match("/([0-9]+)\.([0-9]+)/", $number, $matches);
Solution 18 - Php
If you want the two halves to be explicitly type cast, then sscanf() is a great call.
Code: (Demo)
var_dump(sscanf(1.25, '%d%f'));
Output:
array(2) {
[0]=>
int(1)
[1]=>
float(0.25)
}
Or you can assign the two variables individually:
sscanf(1.25, '%d%f', $int, $float);
var_dump($int);
var_dump($float);
Casting the decimal portion as a float is particularly useful when, say, converting decimal expression of hours to hours and minutes. (Demo)
$decimalTimes = [
6,
7.2,
8.78,
];
foreach ($decimalTimes as $decimalTime) {
sscanf($decimalTime, '%d%f', $hours, $minutes);
printf('%dh%02dm', $hours, round($minutes * 60));
echo "\n";
}
Output:
6h00m
7h12m
8h47m // if round() was not used, this would be 8h46m
Solution 19 - Php
Not seen a simple modulus here...
$number = 1.25;
$wholeAsFloat = floor($number); // 1.00
$wholeAsInt = intval($number); // 1
$decimal = $number % 1; // 0.25
In this case getting both $wholeAs? and $decimal don't depend on the other. (You can just take 1 of the 3 outputs independently.) I've shown $wholeAsFloat and $wholeAsInt because floor() returns a float type number even though the number it returns will always be whole. (This is important if you're passing the result into a type-hinted function parameter.)
I wanted this to split a floating point number of hours/minutes, e.g. 96.25, into hours and minutes separately for a DateInterval instance as 96 hours 15 minutes. I did this as follows:
$interval = new \DateInterval(sprintf("PT%dH%dM", intval($hours), (($hours % 1) * 60)));
I didn't care about seconds in my case.
Solution 20 - Php
val = -3.1234
fraction = abs(val - as.integer(val) )