What's the length of a string?

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how many characters can a Java string have?

How many characters can a string hold at it's maximum. (java)

dup : http://stackoverflow.com/questions/1179983/how-many-characters-can-a-java-string-have — Haim Evgi, Dec 08 '10 at 08:36
it's indeed the same answer. Sorry for the duplicate guys! (and gals) — Demian Kasier, Dec 08 '10 at 08:53

score 3 · Accepted Answer · answered Dec 08 '10 at 08:36

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heap memory is the limit OR the Integer.MAX_VALUE which ever is smaller.

answered Dec 08 '10 at 08:36

jmj

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Not necessarily. I don't know how well various JVMs cope with huge objects (a `char[Integer.MAX_VALUE]` for example) but it's certainly possible to run a JVM with more than that much heap memory... but you'd still be limited in terms of the size of a string. – Jon Skeet Dec 08 '10 at 08:39
@Jon Skeet I didn't get your point how jvm will work on objects which are larger than heap memopry I mean where it will store it ? – jmj Dec 08 '10 at 08:41
My point wasn't about objects larger than heap memory - it was a case of wondering whether the JVM can cope with a single object being nearly 4GB. I know the CLR has (or had) a 1GB-per-object limit, for example. You can use more than 4GB in total in a JVM (if you have the memory) but you can't necessarily create a single object which is that big. – Jon Skeet Dec 08 '10 at 08:46
@Jon Skeet Totally agree with your point – jmj Dec 08 '10 at 08:49
life.java: You can request memory directly from the operating system. Some memory managers do that for objects which are significantly larger then a memory page. The advantage is that the memory can be returned to the OS after usage. Because of fragmentations heap memory can usually not be returned to the OS — But I never heard of a JVM doing that. – Martin Dec 08 '10 at 08:52

score 0 · Answer 2 · answered Dec 08 '10 at 08:39

A lot. Specifically, there does not seem to be any limit, though you will eventually out-of-memory. See the JVM spec for more info, or lack of info: http://java.sun.com/docs/books/jvms/second_edition/html/Concepts.doc.html#25486

EDIT: It looks like Java (the language) allows you to to make a string the length of any single variable, which is probably the amount of heapspace Java has allocated. (see the -Xmx argument).

score 0 · Answer 3 · answered Dec 08 '10 at 08:41

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In theory: 2^31 - 1 = 2147483647 (~2 GigaByte). In practice: end of virtual memory.

answered Dec 08 '10 at 08:41

keval dadia

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score 0 · Answer 4 · answered Dec 08 '10 at 08:42

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Since String is based on an underlying char[], and array indices are int values, the maximum length of a String is Integer.MAX_VALUE, though you'll probably run into memory issues before that.

answered Dec 08 '10 at 08:42

Michael Borgwardt

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What's the length of a string?

4 Answers4