C++ ploblom, the front of "" is mean?

[47803124]

string a=("" + TimeCurrent() + 100+ ";" );

I see have code like that written, what mean? I use FileWrite fuction put the code into xx.txt file,but I can't Read it use FileOpeN- FileReadNumber, I find the cause,possible is the number is oversize,I use WINDOUS XP systom,I Want to Read the Value,What should I do

[qjol]

try FileReadString and StringSubstr then convert it using StringToInteger and StringToTime

or add a "," and use StringSplit then convert it using StringToInteger and StringToTime