Question

我必须创建一个程序，用50个随机值填充数组，介于1和100之间，然后让用户输入1到100之间的数字。程序将输出该数字出现的次数。这是我到目前为止所做的，我不知道接下来要做什么来完成我的计划。

    import java.util.*;

public class Occurences {

public static void main(String[] args)
{
    //This program will generate an array with 50 random values
    //This user will then input a number
    //The program will then tell the user how many times their numbers appears

    //Create array
    int numbers[]= new int[50];

    //Create a new scanner object
    Scanner sc=new Scanner(System.in);

    System.out.println("Please enter a number between 1 and 100");
    int Usernum= sc.nextInt();

    for (int i=0; i<numbers.length; i++)
    {
        numbers[i]=(int)(Math.random()*100+1);

    }

}

}

Answer 1

处理此问题的Java 8之前的方法是迭代随机数组并计算输入发生的次数。添加以下代码：

int count = 0;
for (int i=0; i < numbers.length; i++) {
    if (numbers[i] == Usernum) {
        ++count;
    }
}
System.out.println("The user input " + Usernum + " occurred " + count + " times.");

在Java 8中，我们可以尝试在随机数组上使用流：

int count = Arrays.stream(numbers).filter(x -> x == Usernum).toArray().length;

Answer 2

代码：

package com.stackoverflow.json;

import java.util.Arrays;
import java.util.Scanner;
import java.util.concurrent.ThreadLocalRandom;

public class Main {
public static void main(String[] args) {
    //This program will generate an array with 50 random values
    //This user will then input a number
    //The program will then tell the user how many times their numbers appears

    //Create array
    int numbers[]= new int[50];

    //Create a new scanner object
    Scanner sc=new Scanner(System.in);

    System.out.println("Please enter a number between 1 and 100");
    int Usernum= sc.nextInt();

    for (int i=0; i<numbers.length; i++)
    {
        numbers[i]=ThreadLocalRandom.current().nextInt(1, 100 + 1);;

    }
    System.out.println(Arrays.toString(numbers));
    int count=0;
    for (int i = 0; i < numbers.length; i++) {
        if(numbers[i]==Usernum)
            count++;
    }
    System.out.println("count="+count);

}

}

打印：

Please enter a number between 1 and 100
2
[91, 12, 7, 55, 73, 77, 92, 69, 84, 49, 8, 54, 24, 27, 51, 84, 71, 79, 91, 65, 41, 30, 91, 2, 99, 83, 46, 31, 21, 17, 78, 18, 54, 48, 100, 9, 74, 8, 48, 63, 49, 89, 80, 22, 10, 79, 67, 84, 57, 17]
count=1

java中的随机数组值

2 个答案: