How to truncate decimal value without loosing precision

问题

I have current variable php:

$latlng = "<a href='http://www.google.com/maps/place/".$lat.",".$lng."/@".$lat.",".$lng.",".$zoom."' target='_blank'>Lat ".$lat." Lng ".$lng."</a>";

echo output is as following example:

i want truncate it so at end i want have following result:

I have tried following code but it cut only final part:

$cut_string = substr($latlng,0,strpos($latlng,'</a>')-12);
echo "$cut_string <br/>\r\n";

Thanks

回答1:

I think I understand your problem.
You want the link with full precision but a easy to read link text?

This should be what you need:

$latlng = "<a href='http://www.google.com/maps/place/".$lat.",".$lng."/@".$lat.",".$lng.",".$zoom."' target='_blank'>Lat ".round($lat,3)." Lng ".round($lng,3)."</a>";

As you can see the link to google is intact but the text is rounded to three decimals.

回答2:

You could use round, but you will loose precision. If that works, then

echo round(39.959082, 3);

But, using substr, you could maintain the precision.

$lat = "39.959082";
echo substr($lat,0,strrpos($lat,'.')+4);

will display

39.959

来源：https://stackoverflow.com/questions/46503823/how-to-truncate-decimal-value-without-loosing-precision