问题
I have a simple code first I use this
Long.parseLong(4250120140405520712)
And it works but when I do this
Long.parseLong(42501201404055207123)
It fails. Adding an extra digit makes it throw a Number Format Exception. Can someone please explain
回答1:
Assuming you're parsing Strings into longs:
The first one works because the number 4250120140405520712 (19 digits) is less than the maximum possible long value, Long.MAX_VALUE, 9223372036854775807L.
The second one fails because it's 20 digits long, bigger than 9223372036854775807L.
回答2:
long variables can only hold a maximum of 9223372036854775807 see here for more information.
The reason the second one doesn't work is that you have exceeded the limit so the number format exception is shown.
来源：https://stackoverflow.com/questions/25922439/java-long-parselong-throwing-number-format-exception