java - 我必须在 blueJ 中创建 3 个对象并调用 display() 但我什至无法创建对象。请看代码结果

Question

我必须在blueJ中制作3个对象并调用display()，但我什至无法制作对象。请查看代码结果

public class Project
{
  String Name;
  String deadline;
  String Version;
  double cost;
  public Project(String Name,String deadline,double cost){
      this.Name=Name;
      this.deadline=deadline;
      this.cost=cost;
   }
   public void display(){
    System.out.print("Name of project is: "+this.Name);
    System.out.print("Deadline of the project is: "+this.deadline);
    System.out.print("Cost of the project is: Rs."+this.cost);
   }


}

在尝试创建对象时，会出现一个对话框，其中显示“即使在输入后仍应预期，所以我不知道在哪里输入”

Answer 1

我没有正确理解你的问题...如果你想创建该类的三个对象并希望输出构造函数中传递的属性，你可以这样做:

public static void main(String[] args) {
    List<Project> projects = new ArrayList<>();
    Project pro1 = new Project("Project - X", "deadline - x", 55.12);
    Project pro2 = new Project("Project - Y", "deadline - y", 23655.2);
    Project pro3 = new Project("Project - Z", "deadline - z", 100.00);
    projects.add(pro1);
    projects.add(pro2);
    projects.add(pro3);

    display(projects);


}
static void display(List<Project> pro) {
    for (Project project : pro) {
        System.out.println("Name of project is: " + project.name);
        System.out.println("Deadline of the project is: " + project.deadline);
        System.out.println("Cost of the project is: Rs." + project.cost);
        System.out.println();

    }
}

public static class Project {
    String name;
    String deadline;
    String version;
    double cost;

    public Project(String name, String deadline, double cost) {
        this.name = name;
        this.deadline = deadline;
        this.cost = cost;
    }
}

输出:

Name of project is: Project - X Deadline of the project is: deadline - x Cost of the project is: 55.12

Name of project is: Project - Y Deadline of the project is: deadline - y Cost of the project is: 23655.2

Name of project is: Project - Z Deadline of the project is: deadline - z Cost of the project is: 100.0