Unit 2. Assessment Review

 Unit 2의 평가 문제를 피드백하겠습니다.  Unit 2는 프로그래밍 컨셉, oop를 묻는 내용이 주를 이뤘습니다.

Q1. Describe the programming process

The programming process is an ordered list of steps or stages that is performed to produce a program.

1. Understand the task or problem to be performed or solved

2. Determine a high level strategy for performing the task or solving the problem

3. Elaborate the high level strategy to a detailed strategy that consists of computations that a computer can perform

4. Implement the computations with computer instructions

5. Validate that the execution of the instructions on a computer performs the task or solves the problem of step 1

Q2. Describe the steps of the programming process in terms of software engineering activities.

The programming process consists of:

1. requirement analysis

2. architecture development (high-level design)

3. design ( detailed design)

4. validation.

Q7. What are the fundamental concepts of object-oriented programming?

Object-oriented programming is an approach to solving problems(that is, designing and implementing programs) using objects to describe a real world problems and to build solutions to those problems.  Collections of objects are abstracted to classes.  A class is a collection of objects that have the same data and behave in the same way.  Behavior results from the execution of methods or subroutines on the date values of an object.  Classes are related by inheritance, which means that one class can inherit the data and methods of another class.  

Q8. Name the four key concepts/features of object-oriented programming

1. Modularity

2. Abstraction

3. Composition

4. Hierarchy.

Q9. What are the ‘modules’ in oop called?

Objects, classes

Q11. How is composition done in object-oriented programming

Composition is done in object-oriented programming by the ineraction of objects via messages or calls to their methods.

 질문 중 11번에서 composition은 어떻게 이루어지는지에 대해서 묻는데 그에 대한 대답이 이해가 안가서 찾아보고 정리합니다.

Composition in Java

1. has-a relationship between objects

2. Implemented using instance variables

3. Code reuse

4. Hide visibility to client classes

-Composition Example Code 

package com.journaldev.composition;
 
public class Job {
    private String role;
    private long salary;
    private int id;
        
    public String getRole() {
        return role;
    }
    public void setRole(String role) {
        this.role = role;
    }
    public long getSalary() {
        return salary;
    }
    public void setSalary(long salary) {
        this.salary = salary;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    
    
}
 
package com.journaldev.composition;
 
public class Person {
 
    //composition has-a relationship
    private Job job;
   
    public Person(){
        this.job=new Job();
        job.setSalary(1000L);
    }
    public long getSalary() {
        return job.getSalary();
    }
 
}