Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Is the output of Object.hashCode() required to be the same on all JVM implementations for the same Object?
For example if "test".hashCode() returns 1 on 1.4, could it potentially return 2 running on 1.6. Or what if the operating systems were different, or there was a different processor architecture between instances?
No. The output of
hashCodeis liable to change between JVM implementations and even between different executions of a program on the same JVM.However, in the specific example you gave, the value of
"test".hashCode()will actually be consistent because the implementation ofhashCodeforStringobjects is part of the API ofString(see the Javadocs for java.lang.String and this other SO post).