20,182,316 Hu Park 2019-2020-1 "Object-oriented programming and data structures" lab report 3

Course: "Programming and Data Structures"
Class: 1823
Name: Hu Park
Student ID: 20182316
experiments Teacher: Johnny
experiment Date: 2019 [September 27]
Compulsory / Elective: Compulsory

1. Experimental content

Refer to "experiment two Java object-oriented programming": http: //www.cnblogs.com/rocedu/p/6736847.html
experiment content
Download and install and use the IDEA, following the completion of the experiment (https://www.cnblogs.com/rocedu/p/6371315.html).

Initial grasp of unit testing and TDD
Understand and master the object-oriented three elements: (! Own to learn) encapsulation, inheritance, polymorphism
Preliminary master UML modeling
On completion of the cloud blue ink (1) - (5) experiments.

2. Experimental procedure and results

unit test

Writing Product code MyUtil.java
Writing test code MyUtilTest.java
- project --- new --- Directory
- test --- make directory as --- Test Source Root
TDD use
- File --- settings --- plugins --- junit
- Small bulbs --- creat test
- File --- Project Structure
Test results Screenshot

TDD (Test Driven Devlopment, test-driven development)

Manual play the test program StringBuffer,
AssertEquals way to learn the error code equals (), the modified page
Writing test code according to the above method, were tested three cases: normal normal, unexpected Exception (> 100 / <0), boundary where the boundary (0,60,100 ...)
Test results Screenshot

Complex self-written programs

Pseudo-code (clear program purpose)

复数运算：
定义复数
定义构造函数
定义共有方法：加减乘除

Product Code

public class Complex {
   private double r;
   private double i;
   public Complex(){

   }
   public Complex (double c,double d){
   r=c;
   i=d;
   }
   public static double getreal(double r)
   {
       return r;
   }
   public static double getfake(double i)
   {
       return i;
   }
   public Complex complexadd(Complex c){
       return new Complex(r+c.r,i+c.i);
   }
   public Complex complexsub(Complex c){
       return new Complex(r-c.r,i-c.i);
   }
   public Complex complexcheng(Complex c){
       return new Complex(r*c.r-i*c.i,r*c.i+i*c.r);
   }
   public Complex complexchu(Complex c){
       return new Complex((r*c.r+i*c.i)/(c.r*c.r+c.i*c.i),(i*c.r-r*c.i)/(c.r*c.r+c.i*c.i));
   }
   public String toString(){
       if(i>0)
           return r+"+"+i+"i";
       else if(r==0)
           return r+"";
       else
           return r+""+i+"i";
   }

}

And the results of the test code

uml modeling

Cloud upload code

3. Experimental problems encountered in the process and settlement process

Question 1: occurs when writing test
Problem 1 Solution:
- Class name when writing @Test, the following definitions must start with test, then again on the character you want, otherwise it will error
Question 2: At the time of writing toString method, misunderstood the meaning of the complex real and imaginary parts of the discussion, the negative front of more than a dozen "-."
Problem 2 Solution:
Question 3: Each time a method is called in the complex, you have to fight Complex.xxxx
Question 3 Solution: After the object is instantiated, such as

Complex c1 = new Complex(0, 4);

By then instantiated objects c1, Complex class calls the method:

assertEquals(-1.0, c1.getreal(-1.0));

Question 4: complex operation
Solution:

Sentiment

After the first use of the idea, found it to have advantages and disadvantages, the advantages are numerous, such as using the mouse, there are a variety of abbreviations, file more orderly, more powerful. But compared to the command line, type and number of errors occur more, and many can not read.
In the process of self-study in accordance blog step by step operation, to final completion, although the process is difficult, but let me have a strong sense of accomplishment in helping others and ask other people, have a great harvest.
Thanks sister school seniors guide, gave us great help, very grateful. (⊙ω⊙)

Reference material

Complex algorithms

20,182,316 Hu Park Experiment 3 report