1.实现在控制台输出九九乘法表
public class Test {
public static void main (String[] args) {
for(int i = 0; i <=9; i++){
for(int j = 1; j <= 9; j++){
System.out.print(i + "" + j + “=” + ij + " ");
}
System.out.println();
}
}
}
2.定义方法sum，要求实现两个数之和的运算，要求在main方法中调用
public class Sum {
public static int sum (int i , int j){
return i + j;
}
public static void main (String[] args){
int i = 10;
int j = 10;
System.out.println(sum(i,j));
}
}
3.写出一个方法打印数组的内容，实现遍历数组，要求在main方法中调用
public class Array {
public static void main(String[] args) {
String[] arr1 = { “a”, “b”, “c” };
print(arr1);
}
public static void print(String[] arr) {
for (int i = 0; i < arr.length; i++) {
System.out.print(arr[i]+’,’);
}
}
}
4.抽象类，实现“小明在欧尚买了一件T恤”
首先抽象出衣服人物和超市三个类
public class Cloth {
String name;
public Cloth() {
}
public Cloth(String name) {
super();
this.name = name;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
public class Market {
String name;
public Market() {
}
public Market(String name) {
super();
this.name = name;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
public class People {
String name;
public String getName() {
return name;
}
public People() {
}
public People(String name) {
super();
this.name = name;
}
public void setName(String name) {
this.name = name;
}
}
创建接口
public interface goShopping {
public void shopping(People peo, Market mar, Cloth clo);
}
构造内部实现类
public class goToShopping implements goShopping {
public void shopping(People peo, Market mar, Cloth clo) {
System.out.println(peo.name + “在” + mar.name + “買了” + clo.name );
}
}
实现实现类
public class Test{
public static void main(String[] args) {
People peo = new People();
peo.name = “小明”;
Market mar = new Market();
mar.name = “歐尚”;
Cloth clo = new Cloth();
clo.name = “一件T恤”;
goToShopping go = new goToShopping();
go.shopping(peo,mar,clo);
}
}
5.借助比较器，使用item具备按照价格从高到低排序，初始化10个item，并且Collection sort 进行排序，查看排序结果
首先创建item类
public class Item {
private String name;
private int price;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getPrice() {
return price;
}
public void setPrice(int price) {
this.price = price;
}
@Override
public String toString() {
return “Item [name=” + name + “, price=” + price + “]”;
}
public Item(String name, int price) {
super();
this.name = name;
this.price = price;
}
public Item() {
super();
}
}
创建集合，使用比较器比较
public class Test5 {
public static void main(String[] args) {
List items = new ArrayList<>();
Random r = new Random();
Item a = new Item(“a”, r.nextInt(100));
Item b = new Item(“b”, r.nextInt(100));
Item c = new Item(“c”, r.nextInt(100));
Item d = new Item(“d”, r.nextInt(100));
Item e = new Item(“e”, r.nextInt(100));
Item f = new Item(“f”, r.nextInt(100));
Item g = new Item(“g”, r.nextInt(100));
Item h = new Item(“h”, r.nextInt(100));
Item i = new Item(“i”, r.nextInt(100));
Item j = new Item(“j”, r.nextInt(100));
items.add(a);
items.add(b);
items.add©;
items.add(d);
items.add(e);
items.add(f);
items.add(g);
items.add(h);
items.add(i);
items.add(j);
for (int x = 0; x < items.size(); x++) {
System.out.println(items.get(x) + " ");
}
Comparator y = new Comparator() {
public int compare(Item m1, Item m2) {
if (m2.getPrice() <= m1.getPrice()) {
return 1;
} else {
return -1;
}
}
};
Collections.sort(items, y);
System.out.println(“按照從小到大排序” + items);
}
}