What is the difference of DoubleToStr and DoubleToString?

[Musngi]

What is the difference of DoubleToStr and DoubleToString? I read the documentation but I'm confused because they do the same thing. Can you give me example of uses of this function?

[Ex Ovo Omnia]

The former allows the parameter value 0 through 8, the latter -16 through +16.

[Musngi]

Ovo:
The former allows the parameter value 0 through 8, the latter -16 through +16.

Which is the best function to use?

[Ex Ovo Omnia]

Musngi:
Which is the best function to use?

The better choice is using the MQL5 equivalent, which would make the optional porting easier.