Java基础（数组）数组缩减

public class ArrayTest4 {
    public static void main(String[] args) {
        int[] arr = new int[10];
        for (int i = 0; i < arr.length; i++) {
            arr[i] = (int) (Math.random() * 20);
        }//遍历
        for (int tmp : arr) {
            System.out.print(tmp + " ");
        }
        System.out.println();
        //数组的缩减
        //1.创建新数组
        int [] newArr = new int [arr.length/2];
        //2.依次把老数组中的相应的数据复制到新数组中
        for (int i = 0; i < newArr.length; i++) {
            newArr[i] = arr[i];
        }
        //3.老引用指向新数组，老数组变垃圾
        arr = newArr;
        //遍历
        for (int tmp : arr) {
            System.out.print(tmp + " ");
        }
    }
}

public class StudentTest3 {
    public static void main(String[] args) {
        Student[] stuArr = new Student[15];
        String[] names1 = {"赵", "钱", "孙", "李", "周", "吴", "郑", "王", "冯", "陈", "褚", "卫", "蒋", "沈", "韩", "杨", "朱", "秦", "尤", "许", "穆", "萧", "尹", "姚", "邵", "湛", "汪", "祁", "毛", "禹", "狄", "米", "贝", "明", "臧", "计", "伏", "成", "戴", "谈", "宋", "茅", "庞", "熊", "纪", "舒",
                "毋丘", "贺兰", "綦毋", "屋庐", "独孤", "南郭", "北宫", "王孙"};
        String[] names2 = {"娟", "英", "皋华", "慧", "巧", "美", "静", "晋娜", "翠", "淑", "漆红", "双惠", "竹雅", "珠", "芝", "玉", "萍", "娥", "玲", "挚芬", "芳", "娜", "彩", "云宾", "环", "文惠", "雅", "珠", "春"};
        for (int i = 0; i < stuArr.length; i++) {
            int id = i + 1;
            int index1 = (int) (Math.random() * names1.length);
            int index2 = (int) (Math.random() * names2.length);
            String name = names1[index1] + names2[index2];
            int grade = (int) (Math.random() * 6 + 1);
            double score = (int) (Math.random() * 101);
            stuArr[i] = new Student(id, name, grade, score);
        }
        //遍历
        for (Student tmp :
                stuArr) {
            System.out.println(tmp.toString());
        }
        System.out.println("==========================================================================");
        //1.创建新数组
        Student[] newStuArr = new Student[stuArr.length/2];
        //2.依次把老数组值传入新数组
        for (int i = 0; i < newStuArr.length ; i++) {
            newStuArr[i] = stuArr[i];
        }
        //3.老引用指向新数组
        stuArr = newStuArr;
        //遍历
        for (Student tmp :
                stuArr) {
            System.out.println(tmp.toString());
        }
    }
}