int and Long in Java

Today in the time stamp of the conversion program to find out how to write the wrong, only to find the original

Long A1 = 10;

This code does not directly transform 10 into a long, allocated memory or int length

Need to write long a1 = 10L;

The errors that are very easy to make when writing code are:

Long a3 = 1422206881*1000;

This time 1422206881*1000 obviously has overflowed int length (32 bit), but the compiler does not prompt the error, in memory A3 is an int, only 32 bits are stored.

Then the value of the next A3 is obviously wrong.

SYSTEM.OUT.PRINTLN (A3); The result is shown as: 572706024

The correct notation is to initialize a long type of variable write must be after the number plus L!

int and Long in Java