Multidimensional Arrays
Random rand = new Random();
//定义int数组，从一维到三维
int[] a1 = new int[5];
int[][] a2 = new int[5][5];
int[][][] a3 = new int[5][5][5];
//为生成的数组赋随机值
for (int i = 0; i < a1.length; i++) {
a1[i] = rand.nextInt(1, 101);
}
for (int i = 0; i < a2.length; i++) {
for (int j = 0; j < a2[i].length; j++) {
a2[i][j] = rand.nextInt(1, 101);
}
}
for (int i = 0; i < a3.length; i++) {
for (int j = 0; j < a3[i].length; j++) {
for (int k = 0; k < a3[i][j].length; k++) {
a3[i][j][k] = rand.nextInt(1, 101);
}
}
}
//输出数组
System.out.println(Arrays.toString(a1));
System.out.println(Arrays.deepToString(a2));
System.out.println(Arrays.deepToString(a3));
for (int i = 0; i < a3.length; i++) {
System.out.println(Arrays.deepToString(a3[i]));
}
Integer[] n1 = {
1, 2, 3};
System.out.println(n1);
//数组转换为List
List<Integer> ints = Arrays.asList(n1);
System.out.println(ints);
//asList() 返回List
List<Integer> list = Arrays.asList(1, 2, 3);
System.out.println(list);
int[] n2 = new int[6];
System.out.println(Arrays.toString(n2));
Arrays.fill(n2, 9);
Arrays.fill(n2, 1, 4, 6);
System.out.println(Arrays.toString(n2));
operation result. Among them, Arrays.fill(n2, 1, 4, 6); means to change the value to 6 at the subscripts of 1, 2, and 3 in the n2 array.
Write a message to calculate the time function to realize the data call between methods.
To build a class
public is the access modifier, String is the return value, followed by the method name, and the parameters in parentheses are passed.
public class TimeLiuYan {
public String timeliuyan(int a1, int a2, int a3, int a4, int a5, int a6) {
Calendar cal = Calendar.getInstance();
//获取传递来的时间
cal.set(a1, a2, a3, a4, a5, a6);
//定义格式化时间的形式
SimpleDateFormat simp = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String ms = "时间是：";
//留言时间，将时间转化为时间戳
long t1 = cal.getTimeInMillis();
long t2 = System.currentTimeMillis();
int ts = (int) ((t2 - t1) / (1000));
int tm = (int) ((t2 - t1) / (1000 * 60));
int th = (int) ((t2 - t1) / (1000 * 60 * 60));
int td = (int) ((t2 - t1) / (1000 * 60 * 60 * 24));
if (ts <= 60) {
System.out.print("刚刚：" + ms + "%n");
ms = ms + "刚刚";
} else if (tm >= 1 && tm < 60) {
System.out.printf("%d分钟前：" + ms + "%n", tm);
ms = ms + tm + "分钟前";
} else if (th >= 1 && th < 24) {
System.out.printf("%d小时前：" + ms + "%n", th);
ms = ms + th + "小时前";
} else if (td >= 1 && td < 7) {
ms = ms + td + "天前";
} else {
ms = simp.format(t1);
}
return ms;
}
public String timeliuyan() {
return "";
}
}
Write a main method to call this class
public static void main(String[] args) {
TimeLiuYan t = new TimeLiuYan();
Scanner scan = new Scanner(System.in);
System.out.print("请输入年");
int a1 = scan.nextInt();
System.out.print("请输入月");
int a2 = scan.nextInt();
a2 = a2 - 1;
System.out.print("请输入日");
int a3 = scan.nextInt();
System.out.print("请输入时");
int a4 = scan.nextInt();
System.out.print("请输入分");
int a5 = scan.nextInt();
System.out.print("请输入秒");
int a6 = scan.nextInt();
System.out.println(t.timeliuyan(a1, a2, a3, a4, a5, a6));
}