How can I cast a Long to an int in Java?

Question

Long x;
int y = (int) x;

Eclipse is marking this line with the error:

Can not cast Long to an int

possible duplicate of [How to convert long to int?](http://stackoverflow.com/questions/4355303/how-to-convert-long-to-int) — Bobby, Apr 27 '11 at 08:47
Nope, not a dupe. The other question is about converting a `long`, this one's about converting a `Long`. Big difference! — Sean Patrick Floyd, Apr 27 '11 at 08:52
Note that Long and long are different. "Long" is the class that wraps a value of the primitive type "long". — blizpasta, Apr 27 '11 at 08:53

Sean Patrick Floyd · Accepted Answer · 2011-04-27T09:07:36.137

34

Use primitive long

long x = 23L;
int  y = (int) x;

You can't cast an Object (Long is an Object) to a primitive, the only exception being the corresponding primitive / wrapper type through auto (un) boxing

If you must convert a Long to an int, use Long.intValue():

Long x = 23L;
int  y = x.intValue();

But beware: you may be losing information! A Long / long has 64 bit and can hold much more data than an Integer / int (32 bit only)

edited Apr 27 '11 at 09:07

answered Apr 27 '11 at 08:46

Sean Patrick Floyd

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Also make sure that x is not null, as a Long can be null while a long can't. – Thomas Lötzer Apr 27 '11 at 08:51
@Thomas - Depends on the context, but I can imagine that in case of a null Long, getting a NPE is fine. – Ishtar Apr 27 '11 at 09:21

score 14 · Answer 2 · answered Apr 27 '11 at 08:50

14

Long x is an object.

int y = x.intValue();

answered Apr 27 '11 at 08:50

Ishtar

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score 3 · Answer 3 · answered Apr 27 '11 at 08:50

3

int y = (int) (long) x;

is working.

answered Apr 27 '11 at 08:50

Alex

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IMHO: Double and triple casts tend to be confusing and are best avoided. – Peter Lawrey Apr 27 '11 at 09:10

score 2 · Answer 4 · answered Feb 12 '22 at 18:27

2

Long x1 = 123L;
long x2 = 123L;


int y1 = Math.toIntExact(x1);
int y2 = Math.toIntExact(x2);

This conversion will work with primitive as well as with non-primitive types as well.

answered Feb 12 '22 at 18:27

Aditya Aggarwal

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How can I cast a Long to an int in Java?

4 Answers4