Method equals

src/java/simpledb/storage/TupleDesc.java:226–241

比较type Compares the specified object with this TupleDesc for equality. Two TupleDescs are considered equal if they have the same number of items and if the i-th type in this TupleDesc is equal to the i-th type in o for every i. @param o the Object to be compared for equality with this Tu

(Object o)

     */

    public boolean equals(Object o) {
        // some code goes here
        if (o instanceof TupleDesc){
            List<TDItem> tupleDescList = ((TupleDesc) o).tupleDescList;
            if(tupleDescList.size()==this.tupleDescList.size()){
                for(int i=0;i<this.tupleDescList.size();i++){
                    if(!this.tupleDescList.get(i).getFieldType().equals(tupleDescList.get(i).getFieldType())){
                        return false;
                    }
                }
                return true;
            }
        }

        return false;
    }

    public int hashCode() {
        // If you want to use TupleDesc as keys for HashMap, implement this so