说明:返回将 x 根据指定精度 prec(十进制小数点后数字的数目)进行四舍五入的结果,prec 也可以是负数或零(默认值).
注释:PHP默认不能正确处理类似 "12,300.2" 的字符串.
注释:prec 参数是在 PHP 4 中被引入的,实例代码如下:
PHP
*/
echo round(3.4); //
输出3
echo "
";
echo round(3.5); //
输出4
echo "
";
echo round(3.6); //
输出4
echo "
";
echo round(3.6,0); //
输出4
echo "
";
echo round(1.95583,2); //
输出1.96
echo "
";
echo round(1241757,-3); //
输出1242000
echo "
";
echo round(4.045,2); //
输出4.05
echo "
";
echo round(4.055,2); //
输出4.06
//使用stdround函数代替PHP的round函数
?>
<div class="codetitle"><a style="CURSOR: pointer" data="52931" class="copybut" id="copybut52931" onclick="doCopy('code52931')"> 代码如下:<div class="codebody" id="code52931"><?php
function stdround($num,$d=0)
{
return round($num + 0.0001 / pow(10,$d),$d);
}
echo "round(1.005,2)= ".round(1.005,2). "n ";
echo "round(1.015,2)= ".round(1.015,2). "n ";
echo "round(1.025,2)= ".round(1.025,2). "n ";
echo "round(1.035,2)= ".round(1.035,2). "n ";
echo "round(1.045,2)= ".round(1.045,2). "n ";
echo "round(1.055,2)= ".round(1.055,2). "n ";
echo "round(1.065,2)= ".round(1.065,2). "n ";
echo "round(1.075,2)= ".round(1.075,2). "n ";
echo "round(1.085,2)= ".round(1.085,2). "n ";
echo "round(1.095,2)= ".round(1.095,2). "n ";
echo "stdround(1.005,2)= ".stdround(1.005,2). "n ";
echo "stdround(1.015,2)= ".stdround(1.015,2). "n ";
echo "stdround(1.025,2)= ".stdround(1.025,2). "n ";
echo "stdround(1.035,2)= ".stdround(1.035,2). "n ";
echo "stdround(1.045,2)= ".stdround(1.045,2). "n ";
echo "stdround(1.055,2)= ".stdround(1.055,2). "n ";
echo "stdround(1.065,2)= ".stdround(1.065,2). "n ";
echo "stdround(1.075,2)= ".stdround(1.075,2). "n ";
echo "stdround(1.085,2)= ".stdround(1.085,2). "n ";
echo "stdround(1.095,2)= ".stdround(1.095,2). "n ";
$m=0.000000000000001;
echo "n ";
echo "round(1.005+{$m},2)= ".round(1.005+$m,2). "n ";
echo "round(1.015+{$m},2)= ".round(1.015+$m,2). "n ";
echo "round(1.025+{$m},2)= ".round(1.025+$m,2). "n ";
echo "round(1.035+{$m},2)= ".round(1.035+$m,2). "n ";
echo "round(1.045+{$m},2)= ".round(1.045+$m,2). "n ";
echo "round(1.055+{$m},2)= ".round(1.055+$m,2). "n ";
echo "round(1.065+{$m},2)= ".round(1.065+$m,2). "n ";
echo "round(1.075+{$m},2)= ".round(1.075+$m,2). "n ";
echo "round(1.085+{$m},2)= ".round(1.085+$m,2). "n ";
echo "round(1.095+{$m},2)= ".round(1.095+$m,2). "n ";
echo "round(1.005,2). "n ";
?>
希望本文所述对大家的PHP程序设计有所帮助。
原文链接：https://www.f2er.com/php/23354.html
