显示不带科学计数法的浮点值
当我在 PHP 中进行以下乘法运算时:
When i make the following multiplication in PHP:
$ret = 1.0 * 0.000000001;
我得到结果:1.0E-9
i get the result: 1.0E-9
我想把这个结果转换成普通的十进制符号，我该怎么做?
I want to convert this result into the normal decimal notation, how can i do this?
sprintf('%f',$ret) 不起作用，它返回 0.000000.溢出?
sprintf('%f',$ret) doesn't work, it returns 0.000000. Overflow?
推荐答案
sprintf('%f',$ret)不起作用，它返回0.000000.溢出?
sprintf('%f',$ret)doesn't work, it returns0.000000. Overflow?
sprintf 有效，但是您在这里错过了一些要点.
sprintf works, however you miss some point here.
0.000000 没有溢出.只是 %f 修饰符的 sprintf 默认使用 6 位数字.另外请注意 %f 可以识别区域设置，%F 可能更适合.
0.000000 is not overflow. It's just that sprintf for the %f modifier uses 6 digits per default. Also please take care that %f is locale aware, %F is probably better suited.
您可能想要使用更多数字，例如假设是 4 000 000(四百万):
You might want to use more digits, e.g. let's say 4 000 000 (four million):
$ php -r "printf('%.4000000F', 1*0.000000001);"
Notice: printf(): Requested precision of 4000000 digits was truncated to PHP maximum of 53 digits in Command line code on line 1
Call Stack:
0.0001 319080 1. {main}() Command line code:0
0.0001 319200 2. printf() Command line code:1
0.00000000100000000000000006228159145777985641889706869
如本例所示，不仅有一个公共值(6 位)，还有一个最大值(可能取决于 PHP 执行的计算机系统)，在我的例子中，如警告所示，这里截断为 53 位.
As this example shows, there is not only a common value (6 digits) but also a maximum (probably depended on the computer system PHP executes on), here truncated to 53 digits in my case as the warning shows.
因为你的问题，我想说你想展示:
Because of your question I'd say you want to display:
0.000000001
这是九位数字，所以你需要这样写:
Which are nine digits, so you need to write it that way:
sprintf('%.9F',$ret)
但是，您可能想要这样做:
However, you might want to do this:
rtrim(sprintf('%.20F', $ret), '0');
之后会从右边删除零:
0.000000001
希望这有帮助.
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