Hashcode example sentences

"Hashcode" Example Sentences

1. You override the hashCode() method to generate a hash code for the object.
2. The hashcode is used when putting the object into a HashSet or using it as a key in a HashMap.
3. @Override
public int hashCode() {
int hash = 7;
hash = 31 * hash + this.firstName.hashCode();
hash = 31 * hash + this.lastName.hashCode();
return hash;
}
4. Two objects that are considered equal should have the same hash code.
5. Eclipse can generate a basic hashCode() implementation for you.
6. The default Object class hashCode() implementation returns a random value.
7. You must override both hashCode() and equals() for true object equivalence.
8. Keys in a HashMap must implement hashCode() and equals().
9. A good hashCode() implementation uses all fields that define object equality.
10. The hashCode() contract states that equal objects should return the same hash code.
11. The objects firstName and lastName fields are used to calculate the hash code.
12. The hash code is calculated by multiplying the previous hash by 31 and adding the new field's hashcode.
13. int hash = 7;
hash = 31 * hash + firstName.hashCode();
14. Return a prime number to avoid collisions as much as possible.
15. When the hashcode changes, the object must be removed from any HashSet or HashMap.
16. Hash collisions are resolved using an internal array called a "bucket".
17. LinkedHashMap preserves insertion order by using a linked list.
18. TreeMap uses a Red-Black tree to store keys in sorted order.
19. HashMap uses a hashtable to store key-value pairs for fast lookup.
20. A good hashCode() implementation uses all fields that make up object identity.
21. A bad hashCode() can negatively impact performance of HashSet and HashMap.
22. Double check that equals() and hashCode() are consistent for your objects.
23. Consistent equals() and hashCode() implementations ensure correct Map behavior.
24. Implement Comparable if you want to sort objects of that class.
25. Comparable requires a compareTo() method instead of hashCode().
26. Classes that define their own ordering must implement the Comparable interface.
27. Objects with identical field values should have the same hashcode().
28. Objects that are .equal() should have the same .hashCode().
29. Most fields should be used in calculating the hashcode().
30. Randomizing the hashCode() is usually ineffective and a bad practice.
31. The hashcode() should be deterministic, not random.
32. Avoid using mutable fields to calculate the hashcode().
33. The hashcode() must not change during the object's lifecycle.
34. A hash collision is when two unequal objects have the same hashcode().
35. Hash collisions are handled by chaining or open addressing.
36. Chaining refers to storing collisions in the same bucket.
37. Use Object.hashCode() as a starting point for your hashcode() implementation.
38. Consistent hashcode() implementations ensure correctness for HashMap.
39. A proper hashcode() should evenly distribute hash values.
40. The hashcode() is an object's "identity" for HashSet and HashMap.
41. Explain to new developers why consistent hashCode() methods are important.
42. The hashCode() can change between runs of the same program.
43. The IDE can generate a basic hashCode() to get you started.
44. Unit test hashCode() methods to ensure they meet all requirements.
45. High hash collisions negatively impact HashMap performance.
46. Hash code overloading helps optimize complex object lookups.
47. A good hashCode() maximizes the spread of hash values.
48. Most IDE's can generate a default hashCode() implementation.
49. Object identity must consider value semantics, not reference equality.
50. The hashcode() serves as an object's 'identity' within HashSet and HashMap.
51. A bad hashcode() can cause HashSet and HashMap operations to have O(n) time complexity.
52. We need to rehash objects when their hashcode() changes.
53. HashMap internally uses separate chaining to resolve hash collisions.
54. Separate chaining refers to storing colliding objects in a linked list.
55. Open addressing is another technique HashMap can use to resolve hash collisions.
56. Objects must meet the equals() contract to work properly as Map keys.
57. A good hashCode() is consistent with equals() and use all relevant fields.
58. When calculating the hashcode(), multiply the previous hash by a prime number.
59. Ensure any mutable fields used in hashcode() are not changed during the object's lifetime.
60. Consistent hashCode() and equals() implementations are necessary for correct Map behavior.

Common Phases

1. You override the hashCode() method to generate a hash code for the object.
2. Two objects that are considered equal should have the same hash code.
3. Keys in a HashMap must implement hashCode() and equals().
4. Objects with identical field values should have the same hashcode().
5. Objects that are .equal() should have the same .hashCode().
6. The hashcode() must not change during the object's lifecycle.
7. A hash collision is when two unequal objects have the same hashcode().
8. Consistent hashcode() implementations ensure correctness for HashMap.
9. The hashcode() serves as an object's 'identity' within HashSet and HashMap.
10. A bad hashcode() can cause HashSet and HashMap operations to have O(n) time complexity.