Say I have 1.234 I want to get the .234
I tried echo 1.234%1 //I get 0
I am rusty, what is the correct way?
(The tags says PHP as this might be an issue only with PHP, but I really am looking for the general solution).
php's % modulo operator converts its arguments to integers. To get a floating-point modulus, use fmod:
echo fmod(1.234, 1);
You can remove the whole number from the number itself. in php its:
$num = 1.234;
echo $num - floor($num);
Subtract the integer portion of $x ((int)$x) from $x:
$x = 1.234;
$d = $x - (int)$x;
// $d now equals 0.234
echo $d;
Example
Just substract integer part 1.234 - (int)1.234
Try this:
echo 1.234 - intval(1.234);
Related
I am getting awk result when I am subtracting two values, the error is I am getting exponent value 2.7755575615629E-17 instead of 0. Anything I am missing to apply, please suggest. These is happening with some cases only like 0.66, 0.67, 0.33,
The prototype of the code I am using is given below,
$_SESSION['x'] = 1;
$_SESSION['x'] = $_SESSION['x'] - 0.83;
echo ( $_SESSION['x']- 0.17) ;
echo '<br>';
But on reversing the values It all fine with 0
$_SESSION['x'] = 1;
$_SESSION['x'] = $_SESSION['x'] - 0.17;
echo ( $_SESSION['x']- 0.83) ;
echo '<br>';
This is because its the floating point numbers. And as per the manual
"The size of a float is platform-dependent, although a maximum of ~1.8e308 with a precision of roughly 14 decimal digits is a common value (the 64 bit IEEE format). "
http://php.net/manual/en/language.types.float.php
Now there are 2 things which could be done by using the type cast your result to (int) or round up the result.
The other option is to use the sprintf
Here is an example
$a = 0.00001234;
echo $a ;
The output will be as
1.234E-5
Now if we do
echo (int)$a ;
The output is 0
or
echo round($a) ;
output will be 0
And finally if we do
echo sprintf('%f', $a);
We will get 0.000012
It is a common problem in computer languages - float values aren't represented exactly. See also http://en.wikipedia.org/wiki/Floating_point#Accuracy_problems. If you have a particular amount of decimal places you want to exactly calculate with, you can use the bcmath functions in PHP:
$_SESSION['x'] = 1;
$_SESSION['x'] = bcsub($_SESSION['x'], 0.83, 10);
echo bcsub($_SESSION['x'], 0.17, 10);
echo '<br>';
Otherwise you can simply use your calculation and add an round($result, $numberOfDecimalPlaces) to you calculated result.
How do I output a value as a number in php? I suspect I have a php value but it is outputting as text and not as a number.
Thanks
Here is the code - Updated for David from question below
<?php
if (preg_match('/\-(\d+)\.asp$/', $pagename1, $a))
{
$pageNumber = $a[1];}
else
{ // failed to match number from URL}
}
?>
If I call it in: This code it does not seem to work.
$maxRows_rs_datareviews = 10;
$pageNum_rs_datareviews = $pagename1; <<<<<------ This is where I want to use it.
if (isset($_GET['pageNum_rs_datareviews'])) {
$pageNum_rs_datareviews = $_GET['pageNum_rs_datareviews'];
}
If I make page name a static number like 3 the code works, if I use $pagename1 it does not, this gives me the idea $pagename1 is not seen as a number?
My stupidity!!!! - I used $pagename1 instead of pageNumber
What kind of number? An integer, decimal, float, something else?
Probably the easiest method is to use printf(), eg
printf('The number %d is an integer', $number);
printf('The number %0.2f has two decimal places', $number);
This might be blindingly obvious but it looks like you want to use
$pageNum_rs_datareviews = $pageNumber;
and not
$pageNum_rs_datareviews = $pagename1;
echo (int)$number; // integer 123
echo (float)$number; // float 123.45
would be the easiest
I prefer to use number_format:
echo number_format(56.30124355436,2).'%'; // 56.30%
echo number_format(56.30124355436,0).'%'; // 56%
$num = 5;
echo $num;
Any output is text, since it's output. It doesn't matter what the type of what you're outputting is, since the human eye will see it as text. It's how you actually treat is in the code is what matters.
Converting (casting) a string to a number is different. You can do stuff like:
$num = (int) $string;
$num = intval($string);
Googling php string to number should give you a beautiful array of choices.
Edit: To scrape a number from something, you can use preg_match('/\d+/', $string, $number). $number will now contain all numbers in $string.
get this from my database:
252.587254564
Well i wanna remove the .587254564 and keep the 252, how can i do that?
What function should i use and can you show me an example?
Greetings
You can do it in PHP:
round($val, 0);
or in your MYSQL statement:
select round(foo_value, 0) value from foo
You can do a simply cast to int.
$var = 252.587254564;
$var = (int)$var; // 252
As Tricker mentioned you can round the value down or you can just cast it to int like so:
$variable = 252.587254564; // this is of type double
$variable = (int)$variable; // this will cast the type from double to int causing it to strip the floating point.
In PHP you would use:
$value = floor($value);
floor: Returns the next lowest integer value by rounding the value down if necessary.
If you wanted to round up it would be:
$value = ceil($value);
ceil: Returns the next highest integer value by rounding the value up if necessary.
You can just cast it to an int:
$new = (int)$old;
Convert the float number to string, and use intval to convert it to integer will give you 1990
intval(("19.90"*100).'')
Before using above answer what is your exact requirement please see bellow example output.
$val = 252.587254564;
echo (int)$val; //252
echo round($val, 0); //253
echo ceil($val); //253
$val = 1234567890123456789.512345;
echo (int)$val; //1234567890123456768
echo round($val, 0);//1.2345678901235E+18
echo ceil($val); //1.2345678901235E+18
$val = 123456789012345678912.512345;
echo (int)$val; //-5670419503621177344
echo round($val, 0);//1.2345678901235E+20
echo ceil($val); //1.2345678901235E+20
you can use echo (int) 252.587254564;
positive number:
round(252.587254564) // 253
floor(252.587254564) // 252
ceil(252.587254564) //252
(int)252.587254564 // 252
intval(252.587254564) // 252
~~252.587254564 // 252
negative number:
round(-252.587254564) // -253
floor(-252.587254564) // -253
ceil(-252.587254564) // -252
(int)-252.587254564 // -252
intval(-252.587254564) // -252
~~-252.587254564 // -252
if you want just remove decimals without round you can use one of above codes except round and floor(for negative number).
But I recommended the last one, it's simpler and faster using prefix ~~
And there is also a not quite advisable method:
strtok($value, ".");
This cuts of the first part until it encounters a dot. The result will be a string, not a PHP integer. While it doesn't affect using the result much, it's not the best option.
I see many answers, but the question is:
"Well i wanna remove the .587254564 and keep the 252, how can i do
that?"
Since the questioner is asking for php, the function in php will be the one for the job.
$newValue = floor($value);
In MySQL you can use:
select floor(field)
or in PHP you can use:
floor($value);
example: 1.123 =>1 1.999 => 1
thanks.
$y = 1.235251;
$x = (int)$y;
echo $x; //will echo "1"
Edit:
Using the explicit cast to (int) is the most efficient way to to this AFAIK. Also casting to (int) will cut off the digits after the "." if the number is negative instead of rounding to the next lower negative number:
echo (int)(-3.75); //echoes "-3";
echo floor(-3.75); //echoes "-4";
floor()
will round a number down to the nearest integer.
EDIT: As pointed out by Mark below, this will only work for positive values, which is an important assumption. For negative values, you'd want to use ceil() -- but checking the sign of the input value would be cumbersome and you'd probably want to employ Mark's or TechnoP's (int) cast idea instead. Hope that helps.
You could use a bitwise operator.
Without:
echo 49 / 3;
>> 16.333333333333
With "| 0" bitwise:
echo 49 / 3 | 0;
>> 16
$y = 1.234;
list($y) = explode(".", "$y");
If your input can only be positive floats then as already mentioned floor works.
floor(1.2)
However if your integer could also be negative then floor may not give you what you want: it always rounds down even for negative numbers. Instead you can cast to int as another post mentioned. This will give you the correct result for both negative and positive numbers.
(int)-1.2
To remove all number after point use some php function
echo round(51.5); // Round the number, return 51.
echo floor(51.5); // Round down number, return 51.
echo ceil(51.3); // Round up number, return 52.
How would you find the fractional part of a floating point number in PHP?
For example, if I have the value 1.25, I want to return 0.25.
$x = $x - floor($x)
$x = fmod($x, 1);
Here's a demo:
<?php
$x = 25.3333;
$x = fmod($x, 1);
var_dump($x);
Should ouptut
double(0.3333)
Credit.
Don't forget that you can't trust floating point arithmetic to be 100% accurate. If you're concerned about this, you'll want to look into the BCMath Arbitrary Precision Mathematics functions.
$x = 22.732423423423432;
$x = bcsub(abs($x),floor(abs($x)),20);
You could also hack on the string yourself
$x = 22.732423423423432;
$x = strstr ( $x, '.' );
The answer provided by nlucaroni will only work for positive numbers. A possible solution that works for both positive as well as negative numbers is:
$x = $x - intval($x)
If if the number is negative, you'll have to do this:
$x = abs($x) - floor(abs($x));
My PHP skills are lacking but you could minus the result of a floor from the original number
However, if you are dealing with something like perlin noise or another graphical representation, the solution which was accepted is correct. It will give you the fractional part from the lower number.
i.e:
.25 : 0 is integer below, fractional part is .25
-.25 : -1 is integer below, fractional part is .75
With the other solutions, you will repeat 0 as integer below, and worse, you will get reversed fractional values for all negative numbers.
Some of the preceding answers are partial. This, I believe, is what you need to handle all situations:
function getDecimalPart($floatNum) {
return abs($floatNum - intval($floatNum));
}
$decimalPart = getDecimalPart($floatNum);
You can use fmod function:
$y = fmod($x, 1); //$x = 1.25 $y = 0.25
To stop the confusion on this page actually this is the best answer, which is fast and works for both positive and negative values of $x:
$frac=($x<0) ? $x-ceil($x) : $x-floor($x);
I ran speed tests of 10 million computations on PHP 7.2.15 and even though both solutions give the same results, fmod is slower than floor/ceil.
$frac=($x<0) ? $x-ceil($x) : $x-floor($x);
-> 490-510 ms (depending on the sign of $x)
$frac=fmod($x, 1);
-> 590 - 1000 ms (depending on the value of $x)
Whereas the actual empty loop itself takes 80 ms (which is included in above timings).
Test script:
$x=sqrt(2)-0.41421356237;
$time_start = microtime(true);
for ($i=0;$i<=9999999;$i++) {
//$frac=fmod($x, 1); // version a
$frac=($x<0) ? $x-ceil($x) : $x-floor($x); // version b
}
$time_end = microtime(true);
$time = $time_end - $time_start;