我如何从用户那里获取输入并找到它们的最高、最低和平均值？

Question

我正在编写代码，询问用户的姓名、他们有多少工作以及这些工作的收入。然后代码会找到最高和最低的收入，以及他们输入的工作的平均值。

我遇到了最高和最低支付部分的问题，以及找到平均数，同时仍保留用户输入的内容以便以后复述。

例如： 输入：10000 30000 50000 “你好，奥黛丽。你有 3 个工作。最高薪工作支付 50000 美元。最低薪工作支付 10000 美元。输入的工作的平均工资是 30000 美元

**** 这里是我编辑的代码，但运行不正常。我相信它与int和double有关。我不确定哪些代码应该是 double 的，哪些应该是 int.****

import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
public class JobIncome {


public static void main(String[] args) throws FileNotFoundException {

Scanner input = new Scanner (System.in);
System.out.println("What is your first name? ");
String firstName = input.nextLine();

Scanner scan = new Scanner (System.in);
System.out.println("How many jobs have you had? ");
int jobNum = scan.nextInt();

//Declarations
int total = 0;
int average = 0;

//for loop asks for the incomes of the user's previous 
//jobs and stores them into an array
int arrayOfIncomes[] = new int[jobNum];
for(int i = 1; i <= arrayOfIncomes.length; i++){
    System.out.println("Enter the income of job #" + i + " : ");
    arrayOfIncomes[i] = scan.nextInt();
    total = total + arrayOfIncomes[i];
}

average = total/jobNum;

//Start of the code that will find the min and max
int min = arrayOfIncomes[0];
int max = arrayOfIncomes[0];

for (int i = 1; i < arrayOfIncomes.length; i++) {
    if (arrayOfIncomes[i] > max) {
        max = arrayOfIncomes[i];
    }
}

for (int i = 1; i < arrayOfIncomes.length; i++) {
    if (arrayOfIncomes[i] < min) {
        min = arrayOfIncomes[i];
    }
}

//Print statement that gives the user all their information
System.out.println("Hello, " + firstName + ". You have had" + jobNum + 
"jobs. The highest paying job paid $" + max + 
". The lowest paying job paid $" + min + 
". The average pay for the " + jobNum + "jobs entered is $" + average + ".");


//Prompt asking the user if they would like to print their info into a text file
System.out.println("Would you like to output your information into a text file, yes or no? ");
String yesNo = input.nextLine();
if(yesNo.equals("yes")){
    System.out.println("");
} else {
    System.out.println("Goodbye.");
}


//Output code
Scanner console = new Scanner(System.in);
System.out.print("Your output file: ");
String outputFileName = console.next();
PrintWriter out = new PrintWriter(outputFileName);


//This code prints the information into the output text file
out.print("Hello, " + firstName + ". You have had" + jobNum + 
"jobs. The highest paying job paid $" + max + 
". The lowest paying job paid $" + min + 
". The average pay for the " + jobNum + "jobs entered is $" + average + ".");

out.close();
}

Answer 1

通过实例化一个数组来修复代码，jobIncomes 的长度等于作业的数量。您可以保持运行平均值，但在四舍五入时会丢失精度。您还需要实例化三个整数变量：total、max 和 min，每个变量都为零。

对于循环的每次迭代，您应该添加以下代码：

jobIncomes[i-1]=s.nextInt();
if (jobIncomes[i-1]<min)
{ min=jobIncomes[i-1];}
if (jobIncomes[i-1]>max
{max=jobIncomes[i-1];}
total+=jobIncomes[i-1];

当您打印平均值时，您可以转换公式平均值 = 总计/jobNum。如果您只想在 if 语句中按 i 进行索引，您可能还想将数组值从 0 读取为 jobNum-1。

Answer 2

创建一个 int 变量 sum。当您从用户那里获得输入时添加总和，然后将总和除以变量jobNum，同时将至少一个变量转换为双倍。

例子：

double ave = (double) sum / jobNum;