如何在我的main方法中测试它们，我如何正确实现我的四个方法操作？ [英] How can I implement my four method operations right in order to test them in my main method?
本文介绍了如何在我的main方法中测试它们，我如何正确实现我的四个方法操作？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我把我的java程序分成两类;一个叫做Student类，另一个叫做StudentListing类。我只想弄清楚如何正确地实现四种方法操作，所以我可以在main方法中使用它们进行测试。有人可以帮忙吗？我在挣扎。这是我的两个类的代码。
I have broken my java program down into two classes; one is called a Student class and the other class is called an StudentListing class. I am just trying to figure out how I can correctly implement the four method operations right, so I can use them in the main method for testing purposes. Can someone please help? I am struggling. Here is my code for both classes.
public class Student{
private String name; // key field
private int ID;
private double GPA;
public Student(String name, int ID, double GPA){
this.name= name;
this.ID= ID;
this.GPA=GPA;
}
public void setName(String name){
this.name= name;
}
public String toString() {
return " Student Name: " + name + " Student ID: " + ID + "Student GPA: " + GPA;
}
public String getName() {
return name;
}
public void setID(int ID) {
this.ID= ID;
}
public int getID(){
return ID;
}
public void setGPA(double GPA){
this.GPA= GPA;
}
public double getGPA(){
return GPA;
}
}
public class StudentListings{
private Student[] data; // an array of Student objects
private int next;
private int size;
public StudentListings(){
next=0;
size=100;
data= new Student[size];
}
public StudentListings(int s){
next=0;
data= new Student[s];
size=s;
}
public boolean insert(Student newStudentListing) {
// the structure is full
if(next > = size)
return false;
// store a deep copy of the client's node
data[next]= newStudentListing.deepCopy();
if(data[next]== null)
return false;
next= next + 1; // prepare for the next insert
return true;
}
public StudentListings fetch(String targetKey){
StudentListings student;
StudentListings temp;
// access the node using a sequential search
int i=0;
while(i < next &&!(data[i].compareTo(targetKey)==0)
{
i++;
}
if(i== next) // node not found
return null;
// deep copy the node's information into the client's node
student= data[i].deepCopy();
if(i!= 0) // bubble-up accessed node
{
temp= data[i-1];
data[i-1]=data[i];
data[i]= temp;
}
return student;
}
public boolean delete(String targetKey){
int i=0;
while(i < next && !(data[i].compareTo(targetKey)==0))
{
i++;
}
if(i==next) // node not found
// move the last node into the deleted node's position
return false;
data[i]= data[next-1];
data[next-1]=null;
next= next-1;
return true; // node found and deleted
}
public boolean update(String targetKey, Student newStudentListing){
if(delete(targetKey)== false)
return false;
else if(insert(newStudentListing)==false)
return false;
else
return true;
}
public void showAll(){
for(int i=0; i< next; i++){
System.out.println(data[i].toString());
}
public static void main(String[] args){
StudentListings obj1= new StudentListings();
Student l1 = new Student("Terrence", 1, 3.45);
Student l2 = new Student("Roberta", 2, 2.15);
Student l3 = new Student("George", 3, 1.50);
obj1.insert(l1);
obj1.insert(l2);
obj1.insert(l3);
obj1.ShowAll();
l3= obj1.fetch("Terrence");
System.out.println(l3.toString());
obj1.delete("Roberta");
obj1.ShowAll();
obj1.update("George");
obj1.ShowAll();
}
我的尝试：
我试图在我的主要方法中实现这些方法，但尚未对它们进行测试，因为我需要一些帮助才能首先实现它们。有人可以帮助我吗？
What I have tried:
I have tried to implement these methods in my main method which above but haven't tested them yet because I need some help with implementing them right first. Can someone help me?
推荐答案
package mypackage;
public class Student {
private String name; // key field
private int ID;
private double GPA;
public Student(String name, int ID, double GPA) {
this.name = name;
this.ID = ID;
this.GPA = GPA;
}
public void setName(String name) {
this.name = name;
}
public String toString() {
return " Student Name: " + name + " Student ID: " + ID + " Student GPA: " + GPA;
}
public String getName() {
return name;
}
public void setID(int ID) {
this.ID= ID;
}
public int getID(){
return ID;
}
public void setGPA(double GPA){
this.GPA= GPA;
}
public double getGPA(){
return GPA;
}
}
package mypackage;
public class StudentListings {
// https://www.codeproject.com/Questions/1207978/How-can-I-implement-my-four-method-operations-righ
public static void main(String[] args) {
StudentListings obj1 = new StudentListings();
// NOTE: would stick to avoid using numbers as object names
// this will get messed up if you want to pass them into
// a method as an argument.
Student l1 = new Student("Terrence", 1, 3.45);
Student l2 = new Student("Roberta", 2, 2.15);
Student l3 = new Student("George", 3, 1.50);
Student kid14 = new Student("John", 4, 2.36);
obj1.insert(l1);
obj1.insert(l2);
obj1.insert(l3);
// ERROR: Case sensitive. ShowAll needs to be showAll.
// obj1.ShowAll();
obj1.showAll();
//this call looks good
l3 = obj1.fetch("Terrence");
System.out.println(l3.toString());
//this call looks good
obj1.delete("Roberta");
//this call looks good
obj1.showAll();
// here you are missing the second argument to your method
obj1.update("George", kid14);
//this call looks good
obj1.showAll();
}
private Student[] data; // an array of Student objects
private int next;
private int size;
public StudentListings() {
next = 0;
size = 100;
data = new Student[size];
}
public StudentListings(int s) {
next = 0;
data = new Student[s];
size = s;
}
public boolean insert(Student newStudentListing) {
// the structure is full
if (next >= size) {
return false;
} else {
data[next] = newStudentListing;
next = next + 1; // prepare for the next insert
return true;
}
}
// ERROR: you are trying to assign an object of StudentListings type to a
// Student object
// Public StudentListings fetch(String TargetKey) {
public Student fetch(String TargetKey) {
// StudentListings student;
// StudentListings temp
Student student;
// Access the node using a sequential search
//ERROR: not needed
// int i=0;
// ERROR: why use a while here? Should be a for loop to iterate sequentially
// through your array.
// (I'm guessing) the if the name in data[i] compares to target key that is the
// student
// we want to return
// while(i < next &&!(data[i].compareTo(targetKey)==0)
for (int i = 0; i <= next; i++) {
// if data item == target
if (data[i].getName() == TargetKey) {
student = data[i];
return student;
}
}
// if target does not exist and nothing is retrieved return null
return null;
// not sure what all this is, but its too much.
/* if(i== next) // node not found
return null;
// deep copy the node's information into the client's node
student= data[i].deepCopy();
if(i!= 0) // bubble-up accessed node
{
temp= data[i-1];
data[i-1]=data[i];
data[i]= temp;
}
return student;
}*/
}
public boolean delete(String targetKey) {
boolean deleted = false;
// if you want to use while loops in your functions you should separate the second condition
// to another if statement within it like this:
int i = 0;
// 2 conditions less than count and if we haven't deleted entry yet
while (i < next || deleted == true) {
//put the condition here, so if we find something we can return it
if(data[i].getName() == targetKey) {
//This is where you will put your deletion logic.. I'll leave that to you
}
i++;
}
//don't need this if statement
//if (i == next) // node not found
// move the last node into the deleted node's position
//return false;
//looks like you are attempting to delete the previous record out of the array here but idk.
//either way it is not needed.
//data[i] = data[next - 1];
//data[next - 1] = null;
next = next - 1;
//return deleted instead of true. If it did delete something it will be true, else false
return deleted; // node found and deleted
}
public boolean update(String targetKey, Student newStudentListing) {
if (delete(targetKey) == false)
return false;
else if (insert(newStudentListing) == false)
return false;
else
return true;
}
public void showAll() {
for (int i = 0; i < next; i++) {
System.out.println(data[i].getName() + ", " + data[i].getID() + ", " + data[i].getGPA());
}
}
}
这篇关于如何在我的main方法中测试它们，我如何正确实现我的四个方法操作？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
