java方法参数的传递的练习
题目1

题目展示
package com_itheima.literal;
public class test {
public static void main(String[] args) {
int[] ages={12,20,30,40};
printArray(ages);
System.out.println("----------------");;
int[] numbers={1,2,3,9,12};
printArray(numbers);
int[] numbers1={};
printArray(numbers1);
}
public static void printArray(int[] arr){
System.out.print("[");
if (arr!=null&&arr.length>0)
{
for (int i=0;i<arr.length;i++)
{
System.out.print(i==arr.length-1?arr[i]:arr[i]+", ");
}
}
System.out.println("]");
}
}
题目二:写一个与index相同的算法

题目展示
package com_itheima.literal;
public class test {
public static void main(String[] args) {
int[] arr={11,22,33,66,87,19};
int index=searchIndex(arr,17);
System.out.println("你查询的数据的索引是:"+index);
}
public static int searchIndex(int[] arr,int data){
for(int i=0;i<arr.length;i++)
{
if (arr[i]==data)
{
return i;
}
}
return -1;
}
}
题目三:写一个compare比较函数

题目展示
package com_itheima.literal;
public class test {
public static void main(String[] args) {
int[] arr1={12,120,30};
int[] arr2={12,10,30};
System.out.println(compart(arr1,arr2));
}
public static boolean compart(int[] arr1,int[] arr2){
if (arr1.length== arr2.length)
{
for (int i=0;i<arr1.length;i++)
{
if (arr1[i]!=arr2[i])
{
return false;
}
}
return true;
}
else {
return false;
}
}
}
2 方法重载

代码展示
package com_itheima.literal;
public class test {
public static void main(String[] args) {
fire();
fire("岛国");
fire("岛国",1000);
}
public static void fire(){
System.out.println("默认发射一枚武器给米国。。。");
}
public static void fire(String location){
System.out.println("默认发射一枚武器给米国"+location);
}
public static void fire(String location,int number){
System.out.println("默认发射"+number+"一枚武器给"+location);
}
}
题目二:return关键字:跳出方法

案例
第一道题

package com_itheima.literal;
import java.util.Scanner;
public class test {
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
System.out.println("请您输入机票原价:");
double money=sc.nextDouble();
System.out.println("请您输入机票的月份(1-12): ");
int month=sc.nextInt();
System.out.println("请您选择仓位类型");
String type=sc.next();
System.out.println("机票优惠后的价格是:"+calc(money,month,type));
}
public static double calc(double money,int month,String type){
if (month>=5&&money<=10)
{
switch (type)
{
case "头等舱":
money*=0.9;
break;
case "经济舱":
money*=0.85;
break;
default:
System.out.println("您输入的仓位类型有误");
money=-1;
}
}
else if (month==11||month==12||month>=1&&month<4)
{
switch (type)
{
case "头等舱":
money*=0.7;
break;
case "经济舱":
money*=0.65;
break;
default:
System.out.println("您输入的仓位类型有误");
money=-1;
}
}
else {
System.out.println("对不起,您输入的月份有问题");
money=-1;
}
return money;
}
}
第二道题

代码展示
package com_itheima.literal;
public class test {
public static void main(String[] args) {
for (int i=101;i<=200;i++)
{
boolean flag=true;
for (int j=2;j<i/2;j++)
{
if (i%j==0)
{
flag=false;
break;
}
}
if (flag)
{
System.out.print(i+"\t");
}
}
}
}
第三道题:开发验证码

package com_itheima.literal;
import java.util.Random;
public class test {
public static void main(String[] args) {
String code=createCode(5);
System.out.println("随机验证码:"+code);
}
public static String createCode(int n)
{
String code="";
Random r=new Random();
for(int i=0;i<n;i++)
{
int type=r.nextInt(3);
switch (type)
{
case 0:
char ch=(char)(r.nextInt(26)+65);
code+=ch;
break;
case 1:
char ch1=(char)(r.nextInt(26)+97);
code+=ch1;
break;
case 2:
code+=r.nextInt(10);
break;
}
}
return code;
}
}
第四道题:数组的复制

代码展示
package com_itheima.literal;
import java.util.Random;
public class test {
public static void main(String[] args) {
int[] arr1={11,22,33,44};
int[] arr2=new int[arr1.length];
copy(arr1,arr2);
printArray(arr1);
printArray(arr2);
}
public static void printArray(int[] arr)
{
System.out.print("[");
for (int i=0;i<arr.length;i++)
{
System.out.print(i==arr.length-1?arr[i]:arr[i]+", ");
}
System.out.println("]");
}
public static void copy(int[] arr1,int[] arr2)
{
for (int i=0;i< arr1.length;i++)
{
arr2[i]=arr1[i];
}
}
}
第五道题:评委打分

代码展示
package com_itheima.literal;
import java.util.Scanner;
public class test {
public static void main(String[] args) {
int[] scores=new int[6];
Scanner sc=new Scanner(System.in);
for (int i=0;i< scores.length;i++)
{
System.out.println("请输入第"+(i+1)+"个评委的打分: ");
int score=sc.nextInt();
scores[i]=score;
}
int max=scores[0];
int min=scores[0];
int sum=0;
for(int i=0;i< scores.length;i++)
{
if (scores[i]>max)
{
max=scores[i];
}
if (scores[i]<min)
{
min=scores[i];
}
sum+=scores[i];
}
System.out.println("最高分是:"+max);
System.out.println("最低分是:"+min);
double result=(sum-max-min)*1.0/(scores.length-2);
System.out.println("选手最终的分是: "+result);
}
}