round

(PHP 4, PHP 5, PHP 7)

roundRounds a float

Descrierea

round ( float $val , int $precision = 0 , int $mode = PHP_ROUND_HALF_UP ) : float

Returns the rounded value of val to specified precision (number of digits after the decimal point). precision can also be negative or zero (default).

Parametri

val

The value to round.

precision

The optional number of decimal digits to round to.

If the precision is positive, val is rounded to precision significant digits after the decimal point.

If the precision is negative, val is rounded to precision significant digits before the decimal point, i.e. to the nearest multiple of pow(10, -precision), e.g. for a precision of -1 val is rounded to tens, for a precision of -2 to hundreds, etc.

mode

Use one of the following constants to specify the mode in which rounding occurs.

Constante Descriere
PHP_ROUND_HALF_UP Rounds val away from zero when it is half way there, making 1.5 into 2 and -1.5 into -2.
PHP_ROUND_HALF_DOWN Rounds val towards zero when it is half way there, making 1.5 into 1 and -1.5 into -1.
PHP_ROUND_HALF_EVEN Rounds val towards the nearest even value when it is half way there, making both 1.5 and 2.5 into 2.
PHP_ROUND_HALF_ODD Rounds val towards the nearest odd value when it is half way there, making 1.5 into 1 and and 2.5 into 3.

Valorile întoarse

The value rounded to the given precision as a float.

Exemple

Example #1 round() examples

<?php
var_dump
(round(3.4));
var_dump(round(3.5));
var_dump(round(3.6));
var_dump(round(3.60));
var_dump(round(5.0452));
var_dump(round(5.0552));
var_dump(round(345, -2));
var_dump(round(345, -3));
var_dump(round(678, -2));
var_dump(round(678, -3));
?>

Exemplul de mai sus va afișa:

float(3)
float(4)
float(4)
float(4)
float(5.05)
float(5.06)
float(300)
float(0)
float(700)
float(1000)

Example #2 How precision affects a float

<?php
$number 
135.79;

var_dump(round($number3));
var_dump(round($number2));
var_dump(round($number1));
var_dump(round($number0));
var_dump(round($number, -1));
var_dump(round($number, -2));
var_dump(round($number, -3));
?>

Exemplul de mai sus va afișa:

float(135.79)
float(135.79)
float(135.8)
float(136)
float(140)
float(100)
float(0)

Example #3 mode examples

<?php
echo 'Rounding modes with 9.5' PHP_EOL;
var_dump(round(9.50PHP_ROUND_HALF_UP));
var_dump(round(9.50PHP_ROUND_HALF_DOWN));
var_dump(round(9.50PHP_ROUND_HALF_EVEN));
var_dump(round(9.50PHP_ROUND_HALF_ODD));

echo 
PHP_EOL;
echo 
'Rounding modes with 8.5' PHP_EOL;
var_dump(round(8.50PHP_ROUND_HALF_UP));
var_dump(round(8.50PHP_ROUND_HALF_DOWN));
var_dump(round(8.50PHP_ROUND_HALF_EVEN));
var_dump(round(8.50PHP_ROUND_HALF_ODD));
?>

Exemplul de mai sus va afișa:

Rounding modes with 9.5
float(10)
float(9)
float(10)
float(9)

Rounding modes with 8.5
float(9)
float(8)
float(8)
float(9)

Example #4 mode with precision examples

<?php
echo 'Using PHP_ROUND_HALF_UP with 1 decimal digit precision' PHP_EOL;
var_dump(round1.551PHP_ROUND_HALF_UP));
var_dump(round(-1.551PHP_ROUND_HALF_UP));

echo 
PHP_EOL;
echo 
'Using PHP_ROUND_HALF_DOWN with 1 decimal digit precision' PHP_EOL;
var_dump(round1.551PHP_ROUND_HALF_DOWN));
var_dump(round(-1.551PHP_ROUND_HALF_DOWN));

echo 
PHP_EOL;
echo 
'Using PHP_ROUND_HALF_EVEN with 1 decimal digit precision' PHP_EOL;
var_dump(round1.551PHP_ROUND_HALF_EVEN));
var_dump(round(-1.551PHP_ROUND_HALF_EVEN));

echo 
PHP_EOL;
echo 
'Using PHP_ROUND_HALF_ODD with 1 decimal digit precision' PHP_EOL;
var_dump(round1.551PHP_ROUND_HALF_ODD));
var_dump(round(-1.551PHP_ROUND_HALF_ODD));
?>

Exemplul de mai sus va afișa:

Using PHP_ROUND_HALF_UP with 1 decimal digit precision
float(1.6)
float(-1.6)

Using PHP_ROUND_HALF_DOWN with 1 decimal digit precision
float(1.5)
float(-1.5)

Using PHP_ROUND_HALF_EVEN with 1 decimal digit precision
float(1.6)
float(-1.6)

Using PHP_ROUND_HALF_ODD with 1 decimal digit precision
float(1.5)
float(-1.5)

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