Rounds a float
Syntax
round ( float $val [, int $precision = 0 [, int $mode = PHP_ROUND_HALF_UP ]] ) : float
Parameters
valThe value to round.
precisionThe optional number of decimal digits to round to. If the precision is positive, the rounding will occur after the decimal point. If the precision is negative, the rounding will occur before the decimal point. If the absolute value of the precision is greater than or equal to the number of digits, the result of the rounding is equal to 0
modeUse one of the following constants to specify the mode in which rounding occurs.
| Constants | Description |
|---|---|
| PHP_ROUND_HALF_UP | Round val up to precision decimal places away from zero, when it is half way there. Making 1.5 into 2 and -1.5 into -2. |
| PHP_ROUND_HALF_DOWN | Round val down to precision decimal places towards zero, when it is half way there. Making 1.5 into 1 and -1.5 into -1. |
| PHP_ROUND_HALF_EVEN | Round val to precision decimal places towards the nearest even value. |
| PHP_ROUND_HALF_ODD | Round val to precision decimal places towards the nearest odd value. |
Return
The value rounded to the given precision as a float.
Examples
1 · val · Down
<? $val = 1.4999; $return = round($val); echo $return; ?>
1
2 · val · Up
<? $val = 1.5000; $return = round($val); echo $return; ?>
2
3 · precision
<?
$val = 5555.5555;
for($i = -5; $i < 5; ++$i)
{
$precision = $i;
$return = round($val, $precision);
echo $precision . ": " . $return . PHP_EOL;
}
?>-5: 0 -4: 10000 -3: 6000 -2: 5600 -1: 5560 0: 5556 1: 5555.6 2: 5555.56 3: 5555.556 4: 5555.5555
4 · mode · PHP_ROUND_HALF_UP
<?
$vals = array(-2.5, -1.5, -0.5, 0.5, 1.5, 2.5);
$precision = 0;
$mode = PHP_ROUND_HALF_UP;
for($i = 0; $i < count($vals); ++$i)
{
$return = round($vals[$i], $precision, $mode);
echo $return . PHP_EOL;
}
?>-3 -2 -1 1 2 3
5 · mode · PHP_ROUND_HALF_DOWN
<?
$vals = array(-2.5, -1.5, -0.5, 0.5, 1.5, 2.5);
$precision = 0;
$mode = PHP_ROUND_HALF_DOWN;
for($i = 0; $i < count($vals); ++$i)
{
$return = round($vals[$i], $precision, $mode);
echo $return . PHP_EOL;
}
?>-2 -1 0 0 1 2
6 · mode · PHP_ROUND_HALF_EVEN
<?
$vals = array(-2.5, -1.5, -0.5, 0.5, 1.5, 2.5);
$precision = 0;
$mode = PHP_ROUND_HALF_EVEN;
for($i = 0; $i < count($vals); ++$i)
{
$return = round($vals[$i], $precision, $mode);
echo $return . PHP_EOL;
}
?>-2 -2 0 0 2 2
7 · mode · PHP_ROUND_HALF_ODD
<?
$vals = array(-2.5, -1.5, -0.5, 0.5, 1.5, 2.5);
$precision = 0;
$mode = PHP_ROUND_HALF_ODD;
for($i = 0; $i < count($vals); ++$i)
{
$return = round($vals[$i], $precision, $mode);
echo $return . PHP_EOL;
}
?>-3 -1 -1 1 1 3
