Why the L ? in 86400L for instance ( days from Unixtime )

Projects Programming
1

I must have missed this somewhere, and I have tried searching the forum.

I am building a display that is updated every day at midnight, using a simple RTC for timing ( it has to run for weeks )

To test it without waiting for a whole day each time, I thought I could change the / 86400 for getting days from Unixseconds to say 864, and make it advance 100 times a day .

I dont know why there is the L after the divisor, so can I just use ? int rxday = now.unixtime() / 864L;

Well I tried that and it is working, refreshing every 14.4 minutes, so perhaps the L forces it to a long integer ??

2

Exactly. It is there to tell the compiler to treat the string of digits as a long.

3

you can read up on the C/C++ language and integer literals here:

http://en.cppreference.com/w/cpp/language/integer_literal

and the associated suffix.

4

Thanks guys,

I want to actually study this stuff when I get caught up, but I have been working 14 - 18 hours a day since Christmas ( which is why I havn't been on the forum for a while ) but soon I hope, I can study it a bit and fill in all these many missing gaps of knlowledge .