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javastringhashmapkey-valuebucket

functioning of (== ) in terms of hashCode

String s1="abc";

String s2=new String("abc");

when we compare the both

s1==s2; it return false

and when we compare it with s1.hashCode()==s2.hashCode it return true

i know (==) checks reference id's .Does it returning true in above comparison because above hashCode are saved to same bucket??Please give me explanation

Solution

  • Don't forget that your hash codes are primitive integers, and comparing primitives using == will compare their values, not their references (since primitives don't have references)

    Hence two strings having the same contents will yield the same hash code, and a comparison via == is perfectly valid.

    The concept of a bucket is only valid when you put an object into a hashed collection (e.g. a HashSet). The value of the hash code dictates which bucket the object goes into. The hash codes themselves aren't stored.