java编程，具体问题如下： java 编程问题，如下，
\u95ee\u9898\u5982\u4e0b\uff1a\uff08\u7528java\u5199\u7684\uff09number ++;
\u8fd9\u672c\u8eab\u5c31\u662f\u4e00\u6761\u5b8c\u6574\u7684\u8bed\u53e5\uff0c\u8fd0\u884c\u5b8c\u8fd9\u6761\u65f6\uff0cnumber\u5df2\u7ecf\u81ea\u589e
\u6240\u8c13\u7684\u5148\u4f7f\u7528\u540e\u81ea\u589e\uff0c\u90a3\u662f\u6307\u5728\u540c\u4e00\u8bed\u53e5\u4e2d \u6bd4\u5982 k+number++;
k\u5148\u52a0\u4e0anumber\u7684\u539f\u59cb\u503c\uff0c\u7136\u540enumber\u672c\u8eab\u81ea\u589e1
\u5176\u5b9e k+number++;\u76f8\u5f53\u4e8e\u4e24\u6761\u8bed\u53e5\u4e86 k+number; number=number+1;
String str = "sdsdsd";String start = "";String end = "";String value = str.subString(start.length(),str.length()-end.length()-1);//\u8fd9\u4e2avalue\u5c31\u662f\u4f60\u60f3\u8981\u7684\u8fd9\u4e2a\u65b9\u5f0f\u662f\u7b80\u5355\u7684\uff0c\u524d\u63d0\u662f\u4e0d\u5bb9\u8bb8\u6709\u7a7a\u683c\u7684
集合处理排序问题，可以用java8的stream来搞定
参考代码如下：
public static void main(String[] args) {
Random random = new Random();
IntStream.rangeClosed(1,10).mapToObj(item -> new Student(String.valueOf(item), "Tom" + item, random.nextInt(101)))
.sorted(Comparator.comparing(Student::getScore))
.forEach(item -> System.out.println(item.toString()));
}
public class Student
{
private String id;
private String name;
private int score;
public Student(String id, String name, int score) {
this.id = id;
this.name = name;
this.score = score;
}
@Override
public String toString() {
return "name: "+ this.name + " " + "score: "+ this.score;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getScore() {
return score;
}
public void setScore(int score) {
this.score = score;
}
}上面代码是按照score升序排序的，运行结果如下：
解释一下代码
IntStream.rangeClosed(1,10)：这里生成了1到10个数字的stream
mapToObj：把stream中的数字转化为student对象
sorted：排序，按照student的score进行排序（默认升序）
forEach：循环所有的student，按照toString的方式打印
若想按照降序排列也很简单，在排序处再加一个reversed()方法即可
java8的stream对于集合的相关处理，排序，循环，都很好用，可以去看看
import java.util.Date;
import java.util.Random;
class StudentInfo {
private String id;
private String name;
private int score;
public void setId(String id) {
this.id = id;
}
public String getId() {
return this.id;
}
public void setName(String name) {
this.name = name;
}
public String getName() {
return this.name;
}
public void setScore(int score) {
this.score = score;
}
public int getScore() {
return this.score;
}
public void printStudentInfo() {
System.out.println("**********************");
System.out.println("id:" + this.getId());
System.out.println("name:" + this.getName());
System.out.println("score:" + this.getScore());
}
}
public class Student {
static final int STUDENT_NUM = 10;
static final String ID_START = "10";
static final int SCORE_MAX = 101;
static StudentInfo stu[] = new StudentInfo[10];
static Date date = new Date();
static long seed = date.getTime();
static Random rdm = new Random(seed);
static void studentInit() {
for (int i = 0; i < STUDENT_NUM; i++) {
stu[i] = new StudentInfo();
stu[i].setId(ID_START + Integer.toString(i));
stu[i].setName("tom" + Integer.toString(i+1));
stu[i].setScore(rdm.nextInt(SCORE_MAX));
}
}
static void printStudentsInfo() {
for (int i = 0; i < STUDENT_NUM; i++) {
stu[i].printStudentInfo();
}
}
static void sort() {
StudentInfo s;
for (int i = 0; i < STUDENT_NUM; i++) {
for (int j = 0; j < STUDENT_NUM-i-1; j++) {
if (stu[j].getScore() > stu[j+1].getScore()) {
s = stu[j];
stu[j] = stu[j+1];
stu[j+1] = s;
}
}
}
}
public static void main(String args[]) {
studentInit();
System.out.println("Before sort:");
printStudentsInfo();
sort();
System.out.println("----------------------");
System.out.println("After sort:");
printStudentsInfo();
}
}
学java没多少天，只能写成这样了
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