Third time job

1, a website management system, the user registration, the phone number is optional input, the input format is: Area code-Telephone number-extension number, in the middle with "-" separated. The following is the design on the JSP page and does not have any control over the input.

Suppose the system now needs to take out the middle phone number part, the code is as follows:

/**

*

* This method takes the middle phone number part according to user input.

* @param strphonenum phone number, such as:"0591-83279988-002"

* @return return number section, e.g."83279988"

*/

public string Getphonenumber (string strphonenum) {

if ((strphonenum==null) | | | "". Equals (Strphonenum)) {

Return "";

}

String[] Arrphone=strphonenum.split ("-");

return arrphone[1];

}

Use the techniques and methods you have learned to identify the problems in this approach, and analyze the cause of the problem, and give your solution. (Hint: there is more than one problem)

Requirements:

(1) Write the question

A, whether the input type is a number

B. What is the input length?

(2) Write down the reason why the problem arises

A, no explicitly defined type

B, no clearly defined length

C, no explicit "-" is not required to enter the

(3) Give the modified code

Package Cn.shen.shiyu;

public class Phonenum {

Public String Getphonenumber (int[] quhao,int[] dianhuahao,int[] Fenjihao) {

if (quhao.length==4&&dianhuahao.length==8&fenjihao.length==3) {

Return "true";

}

else if ("". Equals (Quhao) | | " ". Equals (Dianhuahao) | |" ". Equals (Fenjihao)) {

Return "false";

}

return Dianhuahao;

}

}

2, write a paragraph for the integer array sorting code, explain your design ideas, and use the error-guessing method to give a possible error (at least 5), design the test case, and use JUnit to write unit tests to test. (assuming that the passed-in parameter has been determined to be an integer array)

Requirements:

(1) Write code, and conform to code specification (naming to specification, not directly written in the main method, need to have class comments, method comments, and appropriate line comments)

public class Paixu {

/**

* Algorithm for simple sorting

* 2016/04/30

* @author Shenbiling

*/

public static int[] Paixu (int[] a) {

int temp;

Int J;

for (int i=0;i<a.length-1;i++) {

for (j=i+1;j<a.length;j++) {

if (A[i]>a[j]) {

Temp=a[i];

A[I]=A[J];

A[j]=temp;

}

}

}

for (int i:a) {//assigns the value of x to the I output

SYSTEM.OUT.PRINTLN (i + "");

}

return A;

}

public static void Main (string[] args) {

TODO auto-generated Method Stub

Int[] i={0,2,4,8,-3};

SYSTEM.OUT.PRINTLN ("The result after sorting is:");

Paixu (i); Call the Sort Paixu method

System.out.println ();

}

}

(2) Explain your design ideas

A simple comparison sorting algorithm is used.

Idea: the a[0] element is compared with each subsequent element, if a[i] is less than a[0], the two are exchanged, otherwise not exchanged.

(3) Write a possible error (at least five kinds)

A, the number of inputs is 0;

B, enter only one number;

C, the input values are already sorted;

D. The number of inputs is the same

E, the number of inputs are all the same

(4) Write JUnit unit tests to put the test data that was previously given in the possible error into the unit test for testing

A, the number of inputs is 0;

B, enter only one number;

C, the input values are already sorted;

D, the number of inputs are all the same;

E, the number of input parts is the same

Third time job