How to avoid multiple If Statements in Java?

Question

How to refactor this method?

public String getFirstOrLastNameOrBoth() {
    if (this.getFirstname() != null && this.getLastname() != null) {
        return this.getFirstname() + this.getLastname();
    } else if (this.getFirstname() != null && this.getLastname() == null){
        return this.getFirstname();
    } else if (this.getLastname() != null && this.getFirstname() == null){
        return this.getLastname();
    }
    return 0.0;
}

Answer 1

    public String getFirstOrLastNameOrBoth() {
        return (getFirstname() == null ? "" : getFirstname()) 
             + (getLastname() == null ? "" : getLastname());
    }