PHP number format drops zero when rounding [duplicate] - php

This question already has answers here:
Print numeric values to two decimal places
(6 answers)
Closed 11 months ago.
I'm using PHP's number_format to display floats to 2 decimal places.
When the number is something like 1.898 it gets rounded up to 1.9.
How do I get it to display that as 1.90?
Update:
I have a function that ends...
return number_formant($num, 2);
The php script that calls the function prints out the number to be used by Javascript. When I do a var_dump on the number, it prints correctly with two decimal places. Looks like it's Javascript that's loosing the zero.
Here's the JS code that was causing the issue...
function show_level(level) {
...
if (level > 9999)
level_label = (level / 1000).toPrecision(3) + 'k';
else if (level > 999)
level_label = (level / 1000).toPrecision(2) + 'k';
else
level_label = level;
I altered the last line to get it working how I wanted..
level_label = level.toFixed(2);

Maybe not the best solution but:
$n = 1.2345;
$n = number_format( round($n, 1), 2);
//echo 1.20
echo $n;

So,
you mean something like this (what you have):
<?php
echo number_format($x);
?>
and here is what you want:
<?php
echo number_format($x,2);
?>
you can use other lengths. Try it Out!
Hope could helpya
:)

echo sprintf('%01.2f', number_format(1.898,2))

You can do:
echo round(1.898,2);

Related

php round not working when I use float 7 / 100 [duplicate]

This question already has answers here:
Show a number to two decimal places
(25 answers)
Closed 7 years ago.
My code is very simple, for example, my php version is 5.5.11, this is my sample code:
$result = round(($num / 100), 2); // 0.070000000001
$result = $num / 100; // 0.070000000001
I get the $result is 0.070000000001, and if $num = 3, the $result is correct. And I used var_dump($num), the type is the float. how can I fix it?
edit
I found the reason, but I'm not sure the detail. I use Codeigniter, and I load a library PHPExcel, this is third party lib, when I load it, and I will have this problem, but I'm not sure the reason detail.
As I wrote in comment it is connected with how floats are stored in memory
From manual:
Never trust floating number results to the last digit, and do not compare floating point numbers directly for equality. If higher precision is necessary, the arbitrary precision math functions and gmp functions are available.
http://php.net/manual/en/language.types.float.php
I don't know what you want to do with this float variable but if you want to compare then you need some $epsilon
if(abs($a-$b) < $epsilon)
if you want to round then probably you should ignore last digit. number_format() seems like better solution.
This is the issue with floating numbers.
You can even try bccomp
$a = 1.2 * 3;
if (bccomp($a, 3.6) === 0) {
echo 'equal';
} else {
echo 'not equal';
}
//echoes equal
echo "----------------------";
$a = 1.2 * 3;
if ($a == 3.6) {
echo 'equal';
} else {
echo 'not equal';
}
//echoes not equal

Need one digit after decimal without changing any number [duplicate]

This question already has answers here:
Delete digits after two decimal points, without rounding the value
(15 answers)
Closed 8 years ago.
I have a value 3.9609053497942. I need value 3.9 means only one value after decimal. I have used PHP number_format and round functions but it is giving me answer 4.
You could multiply the number by 10, floor() it, and then divide it back.
echo floor($value * 10) / 10;
Try with this,
echo intval((3.9609053497942*10))/10;
or
echo floor((3.9609053497942*10))/10;
There is so many possible solutions:
echo bcadd(3.9609053497942, 0, 1);
preg_match('/\d*\.\d/', 3.9609053497942, $matches);
echo $matches[0];
why not treat it as a string, like
$x = (string)3.96;
$y = explode(".",$x);
$result = $y[0] . "." . $y[1];
Did you tried like:
number_format(3.9609053497942, 1);

PHP rounding error with simple multiplication [duplicate]

This question already has answers here:
Is floating point math broken?
(31 answers)
Closed 3 years ago.
PHP seems to round incorrectly when using (int) to cast variables. Why?
$multiplier = 100000000;
$value = 0.01020637;
echo (int)($value*$multiplier);
Output: 1020636. (unexpected output)
$multiplier = 100000000;
$value = 0.01020637;
echo ($value*$multiplier);
Output: 1020637. (Expected correct output)
Edit: it gets even worse...
$multiplier = 100000000;
$value = 0.01020637;
echo $temp = ($value*$multiplier);
echo '<br/>';
echo (int)$temp;
Output:
1020637
1020636
Things can get hairy when you're dealing with floats, floating point math (and problems involved) are well understood, but can crop up when you're not expecting them. As seems to have happened here. You could read up on the rules extensively, or use language provided tools when handling floating point arithmetic.
When you care about the precision involved you should use the bcmul() function. It's an "optional" extension, but if you care about precision it starts being required rather quickly.
Example:
multiplier = 100000000;
$value = 0.01020637;
echo (int)($value*$multiplier);
echo "\n";
echo bcmul($value, $multiplier, 0);
Sample: http://ideone.com/Wt9kKb
PHP (especially in 32 bit builds) has problems with floating point numbers. This is why casting float into int can have unpredictable results. See PHP Integer page for more detail. Basically, you're getting tiny imprecisions in the math and that can cause serious problems when trying to do something like ceil()
If you really need the numbers converted to int I would suggest you round the numbers first
$multiplier = 100000000;
$value = 0.01020637;
$temp = round($value*$multiplier);
echo $temp . '<br/>' . (int)$temp;
This works by truncating off the small floating point errors. While bcmath can also do the truncation, it's not part of PHP core and not a good overall solution. Your best bet is to write a rounding routine yourself that can return the precision you're looking for. In the project I work on, that was what we did. We wrote our own rounding function and it fixes the problems you'll run into. Without knowing the specifics of what you're trying to do it's hard to say if that's what you need but it's how we did it without bcmath.
The problem you're seeing is the following:
When multiplying two numbers like this:
$mulitply = 0.1 * 100;
You are not multiplying exactly 100 with 0.1, but with with 0.09999999998...
And when it comes to (int), it converts numbers like 4.999 to 4, so your result 1020636.999999999 becomes 1020636 when counting with (int).
bcmul allows for higher precision
$test = (int) bcmul('100000000', '0.01020637');
echo $test
returns the correct answer.
To round floats in PHP you should use the round() function. Just casting to an integer does not round the value correctly.
First argument is which float (the result of your calculation in this case) to be rounded, second is optional, and specifies the amount of decimals (aka precision) being returned. There is also a third argument, controlling the mode. These can be PHP_ROUND_HALF_UP, PHP_ROUND_HALF_DOWN, PHP_ROUND_HALF_EVEN or PHP_ROUND_HALF_ODD.
Example from php.net/round:
<?php
echo round(3.4); // 3
echo round(3.6); // 4
echo round(3.6, 0); // 4
echo round(1.95583, 2); // 1.96
// With the third element, "mode"
echo round(9.5, 0, PHP_ROUND_HALF_UP); // 10
echo round(9.5, 0, PHP_ROUND_HALF_DOWN); // 9
echo round(9.5, 0, PHP_ROUND_HALF_EVEN); // 10
echo round(9.5, 0, PHP_ROUND_HALF_ODD); // 9
?>
An example for your code (live example):
<?php
$multiplier = 100000000;
$value = 0.01020637;
echo intval(round($value*$multiplier)); // Returns 1020637
?>

How to print rounded percent [duplicate]

This question already has answers here:
Print numeric values to two decimal places
(6 answers)
Closed 11 months ago.
hello i'm trying to find %. first i found the seconds
$tm=sum_the_time($d_duration);
$d_seconds='0';
list($hour,$minute,$second) = explode(':', $tm);
$d_seconds += $hour*3600;
$d_seconds += $minute*60;
$d_seconds += $second;
$total_second=$c_seconds+$p_seconds+$t_seconds+$b_seconds+$d_seconds;
$c_seconds=$c_seconds*100/$total_second;
$p_seconds=$p_seconds*100/$total_second;
$t_seconds=$t_seconds*100/$total_second;
$b_seconds=$b_seconds*100/$total_second;
$d_seconds=$d_seconds*100/$total_second;
echo $c_seconds;
the result is 10.754504504505, how would I print this code like 10.7
You can try using printf() function:
printf("%.1f", $c_seconds);
Or, number_format():
echo number_format( $c_seconds, 1 );
These two functions will round your number (will return 10.8 in your example), so, if you want to just truncate to the first decimal place (result to be equal to 10.7), you can use the following:
echo substr($c_seconds, 0, strpos($c_seconds, ".") + 2);
Actually, you can use the solutions from this question to better use number_format() and get your desired result.
echo sprintf('%0.1f', $c_seconds);
relevant docs here: http://php.net/sprintf
http://php.net/manual/en/function.number-format.php numberformat is propably what you are looking for.

Fixing to .2 decimal number [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Default Number of Decimal Places to Output in PHP
basically a bit of a maths problem,
$average_ppm = $total_points_given / $totalvalue;
$average_ppm now equals 2.432608695652174, I don't want to display these numbers, I just need $average_ppm to be 2.43, so to a fixed 2 decimal points. How can I do this??
Thanks for anyones time.
Use sprintf if you want a string output, or round/floor/ceil for a numeric value:
$average_ppm = 2.432608695652174;
echo sprintf("%.2f", $average_ppm); // 2.43
$approx_average_ppm = round($average_ppm, 2);
echo $approx_average_ppm; // 2.43
echo floor($average_ppm, 2); // 2.43 , even if $average_ppm = 2.439
echo ceil($average_ppm, 2); // 2.44
You could either use sprintf, round or floor/ceil depending on how you want the numbers rounded.
Most suited for your need would be round:
$average_ppm = round($total_points_given / $totalvalue,2);
If you want to have ALWAYS 2 numbers after... you can do it with number_format:
number_format(2.43260869565217, 2); // 2.43
When you got a number like: 2.400054846 and you use round you will get 2.4
and if you want it with 2 number behind you can use number_format this will output 2.40
I would use Round:
round($average_ppm, 2);
You could use the bcmath functions if they are available where the third argument is the precision
$average_ppm = bcdiv($total_points_given, $totalvalue, 2);

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