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Java Local Development Environments Advanced Tooling Code Generation

Matthew Francis
Matthew Francis
6,967 Points
Posted by Matthew Francis
Matthew Francis
6,967 Points

Newbie - Why do we need to create hashCode() method when we create equals() method?

What is the purpose of creating hashCode() when we create the equals() method? and when the two methdos are created, what are they overriding?

equals() method:

  public boolean equals(Object obj){
    if(obj == null) return false;
    if(!(obj instanceof Employee)) return false;
    Employee other = (Employee) obj;
    System.out.println(this.employeeId);
    System.out.println(other.employeeId);
    return this.employeeId == other.employeeId;
  }

hashCode() method:

    public int hashCode(){
        final int PRIME = 31;
        int result = 1;
        result = PRIME * result + getId();
        return result;
    }

1 Answer