PHP Tutorial - PHP round() Function
Definition
The round() function rounds a floating-point number to the nearest integer.
Syntax
PHP round() function has following syntax.
float round ( float num [, int precision] ) Parameter
| Parameter | Is Required | Description |
|---|---|---|
| number | Required. | Value to round |
| precision | Optional. | Number of decimal digits to round to. Default is 0 |
| mode | Optional. | Rounding mode: |
The rounding mode value can the one of the following.
- PHP_ROUND_HALF_UP - Default. Rounds number up to precision decimal, when it is half way there. Rounds 1.5 to 2 and -1.5 to -2
- PHP_ROUND_HALF_DOWN - Round number down to precision decimal places, when it is half way there. Rounds 1.5 to 1 and -1.5 to -1
- PHP_ROUND_HALF_EVEN - Round number to precision decimal places towards the next even value
- PHP_ROUND_HALF_ODD - Round number to precision decimal places towards the next odd value
Return
| Item | Value |
|---|---|
| Return Value: | The rounded value |
| Return Type: | Float |
Note
To round a number UP to the nearest integer, use the ceil() function.
To round a number DOWN to the nearest integer, use the floor() function.
Example
If a number is exactly halfway between two integers,
round() will always round up.
If you provide an integer, nothing will happen.
<?PHP//from w w w. j a va2 s .c om
$number = round(11.1); // 11
print $number;
print("\n");
$number = round(11.9); // 12
print $number;
print("\n");
$number = round(11.5); // 12
print $number;
print("\n");
$number = round(11); // 11
print $number;
print("\n");
?>
The code above generates the following result.
Example 2
You can also provide the number of decimal places to round to:
<?PHP//from www.j a va2s . co m
$a = round(4.4999); // 4
print $a;
print("\n");
$b = round(4.123456, 3); // 4.123
print $b;
print("\n");
$c = round(4.12345, 4); // 4.1235
print $c;
print("\n");
$d = round(1000 / 160); // 6
print $d;
?>
The code above generates the following result.
Example 3
Round numbers using the rounding mode constants:
<?php// www . ja va2s . c om
echo(round(1.5,0,PHP_ROUND_HALF_UP) . "\n");
echo(round(-1.5,0,PHP_ROUND_HALF_UP) . "\n");
echo(round(1.5,0,PHP_ROUND_HALF_DOWN) . "\n");
echo(round(-1.5,0,PHP_ROUND_HALF_DOWN) . "\n");
echo(round(1.5,0,PHP_ROUND_HALF_EVEN) . "\n");
echo(round(-1.5,0,PHP_ROUND_HALF_EVEN) . "\n");
echo(round(1.5,0,PHP_ROUND_HALF_ODD) . "\n");
echo(round(-1.5,0,PHP_ROUND_HALF_ODD));
?>
The code above generates the following result.
