While dealing with problems which have values consisting of a very high number of decimal digits such as (121.76763527823) we often come up with a problem of rounding them up. Rounding them up manually can be a very time consuming and erroneous practice. In place of that, an inbuilt function of PHP i.e round() can be used.
The round() function in PHP is used to round a floating-point number. It can be used to define a specific precision value which rounds number according to that precision value.Precision can be also negative or zero.
The round() function in PHP has 3 parameters which are number, precision, and mode among which the latter two are optional parameters.The round() function returns the rounded value of the argument passed.
Syntax:
float round($number, $precision, $mode);
Parameters: It accepts three parameters out of which one is compulsory and two are optional. All of these parameters are described below:
- $number: It is the number which you want to round.
- $precision: It is an optional parameter. It specifies the number of decimal digits to round to. The default value of this parameter is zero.
- $mode: It is an optional parameter. It specifies a constant to specify the rounding mode. The constant can be one of the following:
- PHP_ROUND_HALF_UP: This mode tells to round up the number specified by parameter $number by precision specified by parameter $precision away from zero.
- PHP_ROUND_HALF_DOWN: This mode tells to round up the number specified by parameter $number by precision specified by parameter $precision towards zero.
- PHP_ROUND_HALF_EVEN: This mode tells to round up the number specified by parameter $number by precision specified by parameter $precision towards nearest even value.
- PHP_ROUND_HALF_ODD: This mode tells to round up the number specified by parameter $number by precision specified by parameter $precision towards nearest odd value.
Return Value: It returns the rounded value.
Examples:
Input : round(0.70) Output : 1 Input : round(0.708782) Output : 0.71 Input : round(-3.40) Output : -3 Input : round(-3.60) Output : -4
Below programs illustrate the working of round() in PHP:
- When a parameter is passed with default precision i.e. ‘0’:
PHP
<?php echo(round(0.70)); ?> |
Output:
1
- When a parameter is passed with a specific precision value:
PHP
<?php echo(round(0.70878, 2)); ?> |
Output:
0.71
- When a negative value is passed as a parameter:
PHP
<?php echo(round(-3.40)); ?> |
Output:
-3
- Passing parameters with mode:
PHP
<?php // round to nearest even value echo(round(7.5,0,PHP_ROUND_HALF_EVEN)); echo "\n"; // round to nearest odd value echo(round(7.5,0,PHP_ROUND_HALF_ODD)); echo "\n"; // round towards zero echo(round(7.5,0,PHP_ROUND_HALF_DOWN)); echo "\n"; // round away from zero echo(round(7.5,0,PHP_ROUND_HALF_UP)); ?> |
Output:
8 7 7 8
Important Points To Note:
- round() function is used to round floating-point numbers.
- A specific precision value can be used to get the desired results.
- Precision value can also be negative or zero.
Reference:
http://php.net/manual/en/function.round.php
