请输入10位同学的java成绩，求平均成绩，最高成绩、最低成绩
package zuoye;
import java.util.Scanner;
public class demo4 {
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.println("请输入10个整数:");
int[] arr = new int[10];
for(int i = 0; i < 10;i++){
arr[i]=input.nextInt();
}
int max=maxNum(arr);
System.out.println("最大值是:"+max);
double average=average(arr);
System.out.println("平均值是:"+average);
}
public static int maxNum(int[] arr){
int max = arr[0];
for(int i = 1; i < arr.length; i++){
if(arr[i] > max){
max =arr[i];
}
return max;
}
public static double averageNum(int[] arr){
int sum = 0;
double average = 0;
for(int i = 0; i < arr.length; i++){
sum += arr[i];
}
average=sum /10;
return average;
}
}
}
给定一个数组，判断某个元素是否在该数组中
public class demo4 {
public static void main(String[] args) {
String element = "1";
String[] arr = new String[] {"1","2","3"};
System.out.println(judge(element, arr));
}
public static Boolean judge(String element,String[] arr) {
for (String i : arr) {
if (i == element) {
return true;
}
}
return false;
}
}
给定一个数组，大小为10，输入十个同学的成绩，求这些成绩的总分数
某一天转入2个新同学，请再次求12个同学的平均成绩（尝试着使用扩容的形式做）
package zuoye;
//import java.util.Scanner;
public class demo4 {
public static void main(String[] args) {
int[] arr = new int[]{55,60,66,70,77,80,88,90,99,100};
System.out.println("10人的总成绩是:"+sum(arr));
arr = arr_big(arr,12);
arr[10] = 92;
arr[11] = 90;
for (int i : arr) {
System.out.println(i);
}
System.out.println("12人的平均成绩是:"+avg(arr));
}
public static int sum(int[] arr) {
int sum = 0;
for (int i : arr) {
sum += i;
}
return sum;
}
public static double avg(int[] arr) {
int sum = demo4.sum(arr);
double avg = sum / 10;
return avg;
}
public static int[] arr_big(int[] arr, int len) {
int[] newArr = new int[len];
for (int i = 0; i < arr.length; i++) {
newArr[i] = arr[i];
}
return newArr;
}
}
有一堆硬币，每次只能拿一个或者两个，求最少多少次可以拿完硬币{10, 8, 5, 3, 27, 99}
package zuoye;
//import java.util.Scanner;
public class demo4 {
public static void main(String[] args) {
int[] arr = new int[]{10, 8, 5, 3, 27, 99};
System.out.println(Coin(arr));
}
public static int Coin(int[] arr) {
int count = 0;
for (int i = 0; i < arr.length; i++) {
int num = arr[i];
if (num % 2 == 0) {
count += num / 2;
} else {
count += num / 2 + 1;
}
}
return count;
}
}
将数组中的重复数据去重
package zuoye;
//import java.util.Scanner;
public class demo4 {
public static void main(String[] args) {
int[] arr = new int[]{2,9,9,2,10,21};
int index = 0;
// newArr用来存放不重复的值
int[] newArr = new int[index];
// 对数组进行循环
for (int i = 0; i < arr.length; i++) {
boolean flag = true;
// arr[i] 和 newArr中的数值进行判断
for (int j = 0; j < newArr.length; j++) {
// 如果相等也就是重复，直接结束当前循环
if (arr[i] == newArr[j]) {
flag = false;
break;
}
}
// 如果不重复，先进行数组扩容，再把数据填进去
if (flag) {
index++;
newArr = arr_big(newArr, index);
newArr[index-1] = arr[i];
}
}
for (int i : newArr) {
System.out.println(i);
}
}
public static int[] arr_big(int[] arr, int len) {
int[] newArr = new int[len];
for (int i = 0; i < arr.length; i++) {
newArr[i] = arr[i];
}
return newArr;
}
}
如何将10个0-10随机存入数组中
public class demo4 {
public static void main(String[] args) {
int[] arr = new int[10];
for (int i = 0; i < arr.length; i++) {
arr[i] = random(0,10);
}
for (int i : arr) {
System.out.println(i);
}
}
public static int random(int min, int max) {
return (int) (Math.random() * (max - min) + min);
}
}
执行下列程序的输出结果为 D
public class Test {
public static void main(String[] args) {
String s1 = "HelloWorld";
String s2 = new String("HelloWorld");
if (s1 == s2) {
System.out.println("s1 == s2");
} else {
System.out.println("s1 != s2");
}
if (s1.equals(s2)) {
System.out.println("s1 equals s2");
} else {
System.out.println("s1 not equals s2");
}
}
}
A. s1 == s2
s1 not equals s2
B. s1 == s2
s1 equals s2
C. s1 != s2
s1 not equals s2
D. s1 != s2
s1 equals s2
