在 PHP 中，round() 函数对浮点数进行舍入。本教程演示如何使用 PHP 的 round() 函数。
在 PHP 中舍入浮点数
round() 函数对 PHP 中的浮点数进行舍入。我们可以使用它来定义一个特定的精度值，该值将四舍五入，保持精度值在视图中。
此精度值可以为零或负数。该函数有三个参数；这个函数的语法是：
float round(number, precision, mode);
在哪里：
此方法的返回值是四舍五入的数字。让我们试试这个方法的一个例子。
<?php
$RoundValue1=round(10.3);
$RoundValue2=round(12.5);
$RoundValue3=round(13.6);
$RoundValue4=round(14.6,0);
$RoundValue5=round(6.97553,2);
$RoundValue6=round(7.76521,-3);
$RoundValue7=round(8.063,2);
$RoundValue8=round(9.076,2);
$RoundValue9=round(6.97553, PHP_ROUND_HALF_UP);
$RoundValue10=round(6.97553, PHP_ROUND_HALF_DOWN);
$RoundValue11=round(6.97553, PHP_ROUND_HALF_EVEN);
$RoundValue12=round(6.97553, PHP_ROUND_HALF_ODD) ;
echo "The Round Value for (10.3) is : ". $RoundValue1 . "<br /><br />" ;
echo "The Round Value for (12.5) is : ". $RoundValue2 . "<br /><br />" ;
echo "The Round Value for (13,6) is : ". $RoundValue3 . "<br /><br />" ;
echo "The Round Value for (14.6,0) is : ". $RoundValue4 . "<br /><br />" ;
echo "The Round Value for (6.97553,2) is : ". $RoundValue5 . "<br /><br />" ;
echo "The Round Value for (7.76521,-3) is : ". $RoundValue6 . "<br /><br />" ;
echo "The Round Value for (8.063,2) is : ". $RoundValue7 . "<br /><br />" ;
echo "The Round Value for (9.076,2) is : ". $RoundValue8 . "<br /><br />" ;
echo "The Round Value for (6.97553,2, PHP_ROUND_HALF_UP) is : ". $RoundValue9 . "<br /><br />" ;
echo "The Round Value for (6.97553,2, PHP_ROUND_HALF_DOWN) is : ". $RoundValue10 . "<br /><br />" ;
echo "The Round Value for (6.97553,2, PHP_ROUND_HALF_EVEN) is : ". $RoundValue11 . "<br /><br />" ;
echo "The Round Value for (6.97553,2, PHP_ROUND_HALF_ODD) is : ". $RoundValue12 . "<br /><br />" ;
?>
上面的代码显示了 round() 方法的 12 个不同版本的用法。查看输出：
The Round Value for (10.3) is : 10
The Round Value for (12.5) is : 13
The Round Value for (13,6) is : 14
The Round Value for (14.6,0) is : 15
The Round Value for (6.97553,2) is : 6.98
The Round Value for (7.76521,-3) is : 0
The Round Value for (8.063,2) is : 8.06
The Round Value for (9.076,2) is : 9.08
The Round Value for (6.97553,2, PHP_ROUND_HALF_UP) is : 7
The Round Value for (6.97553,2, PHP_ROUND_HALF_DOWN) is : 6.98
The Round Value for (6.97553,2, PHP_ROUND_HALF_EVEN) is : 6.976
The Round Value for (6.97553,2, PHP_ROUND_HALF_ODD) is : 6.9755
