How to get whole and decimal part of a number?

php math

170,333

Solution 1

$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

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

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

Just to be different :)

list($whole, $decimal) = sscanf(1.5, '%d.%d');

CodePad.

As an added benefit, it will only split where both sides consist of digits.

Solution 5

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

View more solutions

170,333

StackOverflowNewbie

Updated on October 22, 2021

Comments

StackOverflowNewbie about 1 year

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.
- Matt over 11 years
  
  Will a simple explode work? $splitDec = explode(".", $decimal); $splitDec[0] will now by the 1 and splitDec[1] will now be 25 from your example.
- user3167101 over 11 years
  
  @Matt split() has been deprecated.
- Matt over 11 years
  
  @alex yea, forgot. Was thinking javascript. changed to explode.
- shelhamer over 11 years
  
  @Matt, split has been deprecated as of PHP 5.3 and actually takes a regex as its arg, whereas explode takes a string. explode() is preferred in this case.
- Michel about 9 years
  
  Be aware that explode(".",1.10); wil give 1 and 1, not 1 and 10
Jason McCreary over 11 years

As a side, intval() or simple casting as (int) might be more performant than floor()
LanceH over 11 years

How does floor account for negatives?
Brad Christie over 11 years

@LanceH: It doesn't, but you can make it handle it pretty easily with a negative flag.
Michel about 9 years

Be aware that explode(".",1.10); wil give 1 and 1, not 1 and 10
Andreyco about 9 years

This one does not break if number does not contain decimal part. Great!
Andreyco about 9 years

This breaks and throws warning about undefined index, if number is integer or does not contain decimal part.
The Thirsty Ape about 9 years

Nice that this outputs two integers; rather than an int and a float.
Matt James over 8 years

This answer is actually inaccurate unless you add a round(). Sounds dumb, I know, but it has to do with low-level floating point number arithmetic. See here: stackoverflow.com/questions/3726721/php-math-precision
GordonM about 7 years

This assumes that the number is not going to end up being represented in scientific notation when cast to string. If it's a really really huge or really really tiny number then this won't be the case and this method will break.
GordonM about 7 years

This assumes that the number is not going to end up being represented in scientific notation when cast to string. If it's a really really huge or really really tiny number then this won't be the case and this method will break.
Bhargav Rao almost 7 years

Hi, do add a bit of explanation along with the code as it helps to understand your code. Code only answers are frowned upon.
T30 almost 4 years

Try with 510.9, returns 0.89. But can't tell why.
Bitterblue almost 3 years

I accept this answer! It's close to C#'s (a % 1) AND it handles negative numbers well.
Ulrik McArdle over 2 years

Note: if you do this, you should at least use round($decimal, 2); first to ensure you only have two digits as decimal. But you can not use this if you want to have correct math or handle money.
Hamid Naghipour over 2 years

It doesn't work when your number is : $value = 10000000000000.00011111;
Hamid Naghipour over 2 years

And this one dose not work when the number is like this: $value = 10000000000000.00011111;
Hamid Naghipour over 2 years

when the number is something like $value = 10000000000000.00011111; it does not work too
Julien about 2 years

sscanf() first argument should be a string php.net/manual/fr/function.sscanf.php don't forget to cast your float to a string
mickmackusa about 1 year

This answer is not suitable for floats with more or less than 2 decimal places. 3v4l.org/An9gO
mickmackusa about 1 year

These techniques too rigidly require two decimal places in the input.
mickmackusa about 1 year

sscanf() performs greedy matching and variables can be assigned within the function call (list() is not required) stackoverflow.com/a/69039147/2943403
Alberto Guilherme about 1 year

The code did not work with '154.45' it returns 44.
Eric 6 months

@HamidNaghipour It does as long as your processor can handle enough bits. It's a limitation of the computer handling it as a numeric value instead of a string.