二、创建一个People类,包括姓名和年龄2个成员变量。创建3个People对象,将其添加到HashSet中,如果姓名相同,则禁止添加。
时间: 2024-03-09 22:48:33 浏览: 37
好的,我来回答你的问题。
以下是创建People类的代码:
```
public class People {
private String name;
private int age;
public People(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
@Override
public boolean equals(Object obj) {
if (obj == null) return false;
if (obj == this) return true;
if (!(obj instanceof People)) return false;
People p = (People) obj;
return this.name.equals(p.getName());
}
@Override
public int hashCode() {
return name.hashCode();
}
}
```
接下来是添加People对象到HashSet中的代码:
```
HashSet<People> peopleSet = new HashSet<>();
People p1 = new People("Alice", 20);
People p2 = new People("Bob", 30);
People p3 = new People("Alice", 25);
if (peopleSet.add(p1)) {
System.out.println("Successfully added " + p1.getName());
} else {
System.out.println(p1.getName() + " already exists!");
}
if (peopleSet.add(p2)) {
System.out.println("Successfully added " + p2.getName());
} else {
System.out.println(p2.getName() + " already exists!");
}
if (peopleSet.add(p3)) {
System.out.println("Successfully added " + p3.getName());
} else {
System.out.println(p3.getName() + " already exists!");
}
System.out.println("People in the set: ");
for (People p : peopleSet) {
System.out.println(p.getName() + ", " + p.getAge());
}
```
运行结果如下:
```
Successfully added Alice
Successfully added Bob
Alice already exists!
People in the set:
Bob, 30
Alice, 20
```
可以看到,由于p1和p3的姓名相同,所以p3没有被成功添加到HashSet中。
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