PHP: rounding a number and keeping the zeros after comma

In PHP you can use the round() method to round a double. This methods accepts a precision value as second parameter. Some examples:

echo round(3.1415926, 2); // "3.14"
echo round(3.1415926, 3); // "3.142"

When using round() on a value like 3.0000 the conversion to a string will result in just "3":

echo round(3.0000000, 2); // "3"

This is not wrong, but when you want to have a constant precision for different numbers, having an output of "3.00" is much more helpful.

To achieve this, you can use one of the following solutions.

number_format()

echo number_format(3.1415926, 2); // "3.14"

sprintf()

echo sprintf("%.2f", 3.1415926); // "3.14"