PHP: modulo result truncates into two digits - php

I am just wondering why in PHP when I echo the modulo of 123.456 and 100, the result is only 23, but the quotient of 123.456 / 100 is 1.23456. For instance:
<?php
echo 123.456 % 100;
echo 123.456 / 100;
?>
OUTPUT:
23
1.23456
I am expecting that it should return the complete decimal places which is 23456, but it round it off into two decimal places instead. I am new to PHP, and I have no idea if this is a normal behavior of modulo. And if it is, is there any way to get my expected result?
Thanks in advance! :)

What if you force it to be float?
echo (float)(123.456 % 100);
The problem seems to be that it's parsing it as an integer.

Related

How to transform last two numbers to decimal (int to float) in php?

I need transform 100 to 1.00, 345 to 3.45 or any number with 3 digits or more to record in db like a decimal.
Don't need add .00, just transform last two numbers in decimal.
I try number_format($num, 2) but is wrong.
It seems, that you want to divide your numbers to 100, so using number_format() with the appropriate $decimal_separator and $thousands_separator is an option:
<?php
echo number_format($num / 100, 2, '.', '');
?>
Since you are converting from an integer to a float, you can achieve this simply by dividing the number by 100.
$input = 100;
$value = floatval($input) / 100;
$value = number_format($value, 2);
echo $value;
You may then use number_format (as you were using before) to force two decimal places after any evenly divided float numbers (such as 100).
Demo: PHP Sandbox Example

Function round php not work correctly

php function round not working correctly.
I have number 0.9950.
I put code:
$num = round("0.9950", 2);
And I get 1.0? Why?? Why I can't get 0.99?
You can add a third parameter to the function to make it do what you need.
You have to choose from one of the following :
PHP_ROUND_HALF_UP
PHP_ROUND_HALF_DOWN
PHP_ROUND_HALF_EVEN
PHP_ROUND_HALF_ODD
This constants are easy enough to understand, so just use the adapted one :)
In your example, to get 0.99, you'll need to use :
<?php echo round("0.9950", 2, PHP_ROUND_HALF_DOWN); ?>
DEMO
When you round 0.9950 to two decimal places, you get 1.00 because this is how rounding works. If you want an operation which would result in 0.99 then perhaps you are looking for floating point truncation. One option to truncate a floating point number to two decimal places is to multiply by 100, cast to integer, then divide again by 100:
$num = "0.9950";
$output = (int)(100*$num) / 100;
echo $output;
0.99
This trick works because after the first step 0.9950 becomes 99.50, which, when cast to integer becomes just 99, discarding everything after the second decimal place in the original number. Then, we divide again by 100 to restore the original number, minus what we want truncated.
Demo
Just tested in PHP Sandbox... PHP seems funny sometimes.
<?php
$n = 16.90;
echo (100*$n)%100, "\n"; // 89
echo (int)(100*$n)%100, "\n"; // 89
echo 100*($n - (int)($n)), "\n"; // 90
echo (int)(100*($n - (int)($n))), "\n"; // 89
echo round(100*($n - (int)($n))), "\n"; // 90

is possible to less float values..?

$quantity = 20;
$product_rate = 66.79;
$total = $quantity * $product_rate;
echo $total;
Output is showing 1335.8000000000002
is there possible to show 1335.8 using php..?
You can use the number_format() function like this:
$firstNum = 1335.8000000000002;
$number = number_format($firstNum, 1, '.', '');
echo $number;
outputs:
1335.8
more on number_format() here: http://php.net/number-format.
You can also multiply the number by 10, then use intval() to convert it to an integer (that way stripping out the decimals) and then divide by 10 like this:
$firstNum = 1335.8000000000002;
$number = 10 * intval($firstNum)/10;
echo $number;
outputs:
1335.8
Note: when using the methods above there will be no rounding, for rounding you would use something like this:
$number = round($firstNum, 1);
echo $number;
which in this case also outputs:
1335.8
Do you really use these variable values? I'm using PHP7 and the output for your given values is 1335.8. If you do a manual calculation it is the same result. It should be 1335.8. Anyway if you need to roundup the value you can use below.
round($total,1);
Please refer the below link and you will be able to grab more details.
http://php.net/manual/en/function.round.php
Because how floating point numbers work, they cannot represent every numbers exactly, so approximations are made.
The closest representation of 20 is 20, it can represent 20 exactly, but 66.79 for instance is approximated to 66.7900000000000062527760746889, that times 20 is 1335.800000000000125055521493778 that again cannot be represented and is approximated to 1335.80000000000018189894035459.
Depending on how you choose to print this number, it may round different ways, in your case for some reason you decided to print 13 decimal places so it rounded to 1335.8000000000002, but if you print only 1 or 2 decimal places it will print as 1335.8 or 1335.80. Just be mindful about that when printing floating point numbers, you may want to specify how many decimal places are relevant to you. For that, use number_format().
Example:
echo number_format($number, 2); // prints 2 decimal places
You can do this simply using echo echo round($total, 1) instead of doing round($total)

number formatting in php

I want to format numbers like following
13.20 to 13.2
13.34 to 13.34
13.00 to 13
I have tried to use a combination of str_replace() and number_format() but not able to produce required result.
Please help me, if anyone have any idea.
Thanks in advance
Try using the built-in round function:
echo round(1.23456, 2);
This will return 1.23. Of course, you have to decide how many numbers after the decimal point to keep.
number_format should work:
<?php
$number = 12.345;
echo number_format($number, 1); # Produces number with one decimal precision.
?>
EDIT:
<?php
$number = 12.30;
#Strips ZEROs and decimal point from the end
echo rtrim($number, '0.'); #Result: 12.3
?>
Or just simply, this is magic :
$number + 0
// 12.30 + 0 = 12.3
Or you can cast your number to float :
echo floatval($number);
It depends on the type of variable you're using. A string 13.20 will output 13.20 but a float 13.20 will output 13.2.
All you have to do is cast it:
echo (float) '13.20'; // Will output 13.2

How to delete all numbers after point in PHP

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.

Categories