1 package com.jdk7.chapter4;
2
3 import java.text.DecimalFormat;
4 import java.util.Arrays;
5
6 /**
7 * 数组的加减乘除
8 * @author Administrator
9 *
10 */
11
12 public class MatrixData
implements Cloneable{
13 //声明一个私有double类型的二维数组存放数据,私有变量只能在该类中使用，不能被外部调用
14 private double[][] matrixData;
15
16 //无参构造函数
17 public MatrixData(){
18 //用默认值进行初始化
19 this.init();
20 }
21
22 //带参构造函数
23 public MatrixData(
double[][] b){
24 //二维数组b为空则调用默认值进行初始化
25 if(!
arraySameLength(b)){
26 System.out.println("数组第二维长度不等"
);
27 this.init();
28 }
else{
//二维数组b不为空，则将b克隆
29 System.out.println("数组第二维长度都相等"
);
30 this.matrixData =
b;
31 }
32 }
33
34 public MatrixData add(MatrixData data){
35 if(data==
null){
return null;}
36
37 double[][] datab =
data.getMatrixData();
38 MatrixData c =
null;
39 if(!
sameLength(data)){
40 return c;
41 }
else{
42 double[][] datac =
new double[
this.matrixData.length][
this.matrixData[0
].length];
43 for(
int i=0;i<
this.matrixData.length;i++
){
44 for(
int j=0;j<
this.matrixData[0].length;j++
){
45 datac[i][j] =
this.matrixData[i][j] +
data.matrixData[i][j];
46 }
47 }
48 c =
new MatrixData(datac);
49 return c;
50 }
51 }
52
53 public MatrixData sub(MatrixData b){
54 if(b==
null){
return null;}
55 double[][] datab =
b.getMatrixData();
56 MatrixData c =
null;
57 if(sameLength(b)){
58 double[][] datac =
new double[
this.matrixData.length][
this.matrixData[0
].length];
59 for(
int i=0;i<
this.matrixData.length;i++
){
60 for(
int j=0;j<
this.matrixData[0].length;j++
){
61 datac[i][j] =
this.matrixData[i][j] -
datab[i][j];
62 }
63 }
64 c =
new MatrixData(datac);
65 return c;
66 }
else{
67 return c;
68 }
69 }
70
71 public MatrixData multiply(MatrixData data){
72 if(data==
null){
return null;}
73 double[][] datab =
data.getMatrixData();
74 MatrixData c =
null;
75 if(sameLength(data)){
76 double[][] datac =
new double[
this.matrixData.length][
this.matrixData[0
].length];
77 for(
int i=0;i<
this.matrixData.length;i++
){
78 for(
int j=0;j<
this.matrixData[0].length;j++
){
79 datac[i][j] =
this.matrixData[i][j] *
datab[i][j];
80 }
81 }
82 c =
new MatrixData(datac);
83 return c;
84 }
else{
85 return c;
86 }
87 }
88
89 public MatrixData division(MatrixData data){
90 if(data==
null){
return null;}
91 double[][] datax =
data.getMatrixData();
92 MatrixData c =
null;
93 if(sameLength(data)){
94 double[][] datac =
new double[
this.matrixData.length][
this.matrixData[0
].length];
95 for(
int i=0;i<
this.matrixData.length;i++
){
96 for(
int j=0;j<
this.matrixData[0].length;j++
){
97 if(datax[i][j]==0
){
98 System.out.println("商不能为零"
);
99 break;
100 }
else{
101 datac[i][j] = (
this.matrixData[i][j] /
datax[i][j]);
102 }
103 }
104 }
105 c =
new MatrixData(datac);
106 return c;
107 }
else{
108 return c;
109 }
110 }
111
112 //判断二维长度是否相等
113 public boolean sameLength(MatrixData b){
114 if(
this.matrixData.length != b.matrixData.length ||
this.matrixData[0].length != b.matrixData[0
].length){
115 return false;
116 }
else{
117 return true;
118 }
119 }
120
121 //默认的二维数组
122 private void init() {
123 this.matrixData =
new double[][]{{1,2,0},{4,5,6},{7,8,9
}};
124 }
125
126 public double[][] getMatrixData() {
127 return matrixData;
128 }
129
130 public void setMatrixData(
double[][] matrixData) {
131 this.matrixData =
matrixData;
132 }
133
134 public Object clone(){
135 try {
136 System.out.println("调用clone方法"
);
137 MatrixData src = (MatrixData)
super.clone();
138 src.setMatrixData(
this.matrixData);
139 return src;
140 }
catch (CloneNotSupportedException e) {
141 e.printStackTrace();
142 }
143 return null;
144 }
145
146 public int hashCode(){
147 return this.toString().hashCode();
148 }
149
150 /**
151 * 在比较的过程中涉及到多层嵌套条件判断，最外层的正反两面都要给予对应的返回结果，如果内层的返回结果同外层不一致，则需指定确切的返回结果，
152 * 反面情况保持默认的返回结果
153 */
154 public boolean equals(Object data){
155 if(data==
null){
156 return false;
157 }
158 if(data
instanceof MatrixData){
159 MatrixData datax =
(MatrixData) data;
160 if(sameLength(datax)){
161 for(
int i=0;i<
this.matrixData.length;i++
){
162 for(
int j=0;j<
this.matrixData[0].length;j++
){
163 if(
this.matrixData[i][j] !=
datax.matrixData[i][j]){
164 return false;
165 }
166 }
167 }
168 }
169 return true;
170 }
else{
return false;}
171 }
172 //二位数组的二维长度相等
173 public boolean arraySameLength(
double[][] b){
174 for(
int i=0;i<b.length-1;i++
){
175 if(b[i].length != b[i+1
].length){
176 return false;
177 }
178 }
179 return true;
180 }
181
182 //将所有的打印信息放入StringBuffer中再转换为String类型，包括空格和换行
183 public String arrayToString(
double[][] b){
184 StringBuffer sb =
new StringBuffer(""
);
185
186 //按照指定的格式进行格式化
187 DecimalFormat df =
new DecimalFormat();
188 String pattern = "0.00"
;
189 df.applyPattern(pattern);
190
191 for(
int i=0;i<b.length;i++
){
192 for(
int j=0;j<b[0].length;j++
){
193 // sb.append((Double.valueOf(b[i][j])).toString()).append(" ");
194 sb.append(df.format((Double.valueOf(b[i][j]))).toString()).append(" "
);
195 }
196 sb.append("\n"
);
197 }
198 return sb.toString();
199 }
200
201 @Override
202 public String toString() {
203 // return "MatrixData [matrixData=" + Arrays.toString(matrixData) + "]";
204 return this.arrayToString(
this.matrixData);
205 }
206
207 public void display(){
208 System.out.println(
this.toString());
209 }
210
211 }
1 package com.jdk7.chapter4;
2
3 public class Test {
4 public static void main(String[] args) {
5 double[][] array0 =
new double[][]{{9.0,8.0,7.0},{6.0,5.0,4.0},{3.0,2.0,1.0
}};
6 MatrixData m0 =
new MatrixData(array0);
7 MatrixData m1 =
new MatrixData();
8 System.out.print("数组m0为: "
);
9 m0.display();
10 System.out.print("数组m1为: "
);
11 m1.display();
12 System.out.print("数组(m0 + m1)为: "
);
13 m0.add(m1).display();
14 System.out.print("数组(m0 - m1)为: "
);
15 m0.sub(m1).display();
16 System.out.print("数组(m0 * m1)为: "
);
17 m0.multiply(m1).display();
18 MatrixData m2 =
(MatrixData)m0.clone();
19 System.out.print("从m0克隆的m2为: "
);
20 m2.display();
21 System.out.println("m0的哈希码为: "+
m0.hashCode());
22 System.out.println("m2的哈希码为: "+
m2.hashCode());
23 System.out.println("m0和m2是否相等: "+
m0.equals(m2));
24 System.out.print("数组m3为: "
);
25 MatrixData m3 =
null;
26 UsingArrays ua =
new UsingArrays();
27 System.out.println("m0和m3是否相等: "+
m0.equals(m3));
28 System.out.println("m0和m1是否相等: "+
m0.equals(m1));
29 System.out.println("m0和ua是否相等: "+
m0.equals(ua));
30
31 System.out.print("数组(m0 / m1)为: "
);
32 m0.division(m1).display();
33 }
34
35 }
36
37
38 执行结果：
39 数组第二维长度都相等
40 数组m0为: 9.00 8.00 7.00
41 6.00 5.00 4.00
42 3.00 2.00 1.00
43
44 数组m1为: 1.00 2.00 0.00
45 4.00 5.00 6.00
46 7.00 8.00 9.00
47
48 数组(m0 +
m1)为: 数组第二维长度都相等
49 10.00 10.00 7.00
50 10.00 10.00 10.00
51 10.00 10.00 10.00
52
53 数组(m0 -
m1)为: 数组第二维长度都相等
54 8.00 6.00 7.00
55 2.00 0.00 -2.00
56 -4.00 -6.00 -8.00
57
58 数组(m0 *
m1)为: 数组第二维长度都相等
59 9.00 16.00 0.00
60 24.00 25.00 24.00
61 21.00 16.00 9.00
62
63 调用clone方法
64 从m0克隆的m2为: 9.00 8.00 7.00
65 6.00 5.00 4.00
66 3.00 2.00 1.00
67
68 m0的哈希码为: 363974377
69 m2的哈希码为: 363974377
70 m0和m2是否相等:
true
71 数组m3为: m0和m3是否相等:
false
72 m0和m1是否相等:
false
73 m0和ua是否相等:
false
74 数组(m0 /
m1)为: 商不能为零
75 数组第二维长度都相等
76 9.00 4.00 0.00
77 1.50 1.00 0.67
78 0.43 0.25 0.11
转载于:https://www.cnblogs.com/celine/p/8428326.html
