JAVASE基础（数组——猜数字与打印三角形）

数组示例

自定义数字

package com.lhs;

import java.util.Scanner;

public class Test4 {
    public static void main(String[] args) {
    	//自定义一组数组
        int[] nums  = {12,23,43,32,24,23};
        Scanner input = new Scanner(System.in);
        System.out.println("请输入您要查找的数字：");
        int userNum = input.nextInt();
		//默认猜错了
        boolean flag = false;
        for(int x:nums){
            if (userNum==x){
                flag = true;
                break;
            }
        }

        if (flag){
            System.out.println("猜对了");
        }else {
            System.out.println("猜错了");
        }
    }
}

使用随机数猜数字

package com.lhs;

import java.util.Random;
import java.util.Scanner;

public class Test5 {
    public static void main(String[] args) {

        int[] nums  = new int[5];
        int len = nums.length;
        //使用随机数，并将数字存到数组中
        Random r = new Random();
        for (int i = 0; i < len; i++) {
        //设置范围
           nums[i] = r.nextInt(50);
        }
        Scanner input = new Scanner(System.in);
        System.out.println("请输入您要查找的数字：");
        int userNum = input.nextInt();

        boolean flag = false;
        for(int x:nums){
            if (userNum==x){
                flag = true;
                break;
            }
        }

        if (flag){
            System.out.println("猜对了");
        }else {
            System.out.println("猜错了");
        }
    }
}

打印三角形

package com.lhs;

public class Test6 {
    public static void main(String[] args) {
        char[] cs = {'A','B','C','D','E','F','G'};
        int len = cs.length;
        for (int i = 1; i <= len; i++) {
            for (int j = i; j <=len; j++) {
                System.out.print(" ");
            }
            for (int j= 1;j<=i*2-1;j++){
                System.out.print(cs[i-1]);
            }
            System.out.println();
        }
    }
}