Using getClass.equals(otherObj.getClass()) in an implementation of equals(Object otherObj)-CodePudding

A boilerplate implementation of an equals(Object otherObj) reads like this:

@Override
    public boolean equals(Object other)
    {
        if(this == other)
            return true;
        if(other == null)
            return false;
        if(this.getClass() != other.getClass())
            return false;
        Employee e = (Employee) other;
        return (Objects.equals(this.name, e.name) && 
                Objects.equals(this.hireDay, e.hireDay) && 
                this.salary == e.salary);      
    }

Can we use:

if(!this.getClass().equals(other.getClass()))

instead?

CodePudding user response：

Class<T> does not override equals and uses the default Object#equals(Object) implementation. Therefore, a.getClass().equals(b.getClass()) is equivalent to a.getClass() == b.getClass()

Object#equals(Object) is implemented as:

public boolean equals(Object obj) {
    return (this == obj);
}

CodePudding user response：

a.getClass().equals(b.getClass()) is equivalent to a.getClass() == b.getClass(), it can't instead the above equal method.