泛型

// 泛型类
public class Box<T> {
    private T content;

    public void set(T content) {
        this.content = content;
    }

    public T get() {
        return content;
    }
}

// 使用泛型类
Box<String> stringBox = new Box<>();
stringBox.set("Hello");
String s = stringBox.get();

Box<Integer> intBox = new Box<>();
intBox.set(100);
int n = intBox.get();

// 泛型方法
public static <T> void printArray(T[] array) {
    for (T element : array) {
        System.out.println(element);
    }
}