如何从用户输入中找到最大的数字和最小的数字？ （同时循环）

Question

Not sure where to begin honestly, I was able to find average using the user's input but can't seem to figure out the largest number or the smallest number from the numbers entered. Is there a method I can use? Any help would be great. Thank you.

EDIT: Somewhat figured it out. However the answers always seem to be largest number = 2.1478... or Smallest number = -2.1478...

Scanner input = new Scanner(System.in);


System.out.println("Enter the number of grades: ");
double random = input.nextDouble();
double min = Integer.MIN_VALUE;
double max = Integer.MAX_VALUE;

double total=0;
int count = 1;
while (count < random+1) {




    System.out.println("Enter grade " + count + ":");

    double somenumber = input.nextDouble();
    total+=somenumber;

    count++;

    if (somenumber > max){
        max = somenumber;
    }
if (somenumber < min){
    min = somenumber;
}


}
System.out.println("Total is " + total);
System.out.println("Average is " + (total/random));
System.out.println("Largest number is " + max);
System.out.println("Smallest number is" + min);



        }

}

Answer 1

You want some code that looks like

double min = Double.MAX_VALUE;
double max = 0.00;  // assume use positive numbers

while (count < random+1) {

System.out.println("Enter grade " + count + ":");

double somenumber = input.nextDouble();
total+=somenumber;

count++;

max = Math.max (somenumber, max);
min = Math.min (somenumber, min);

}

Answer 2

EDIT Updated to use Double instead and now uses your original loop condition.

import java.util.Scanner;

public class Test {

    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);
        double smallest = Double.POSITIVE_INFINITY; //Initialize to largest int possible
        double largest = Double.NEGATIVE_INFINITY; //Initialize to smallest int possible
        System.out.println("Enter the number of grades: ");
        double random = input.nextDouble();
        int count = 1;

        while (count < random + 1) {
            System.out.print("Input Number: ");
            Double x = input.nextDouble();
            if (x < smallest) {
                smallest = x;
            }
            if (x > largest) {
                largest = x;
            }
            count++;
        }
        System.out.println("Smallest: " + smallest + ", Largest: " + largest);
    }
}

Sample run:

run:
Enter the number of grades:
5
Input Number: 2.5454
Input Number: 3.454
Input Number: -100.54
Input Number: 5687
Input Number: 579873.5654
Smallest: -100.54, Largest: 579873.5654
BUILD SUCCESSFUL (total time: 15 seconds)

Answer 3

Thank you for the tips everyone. However, when I ran my program. I wasn't able to get the proper answers for the max and min value.

EDIT: SOLVED. THANK YOU ALL WHO CONTRIBUTED. <33

Scanner input = new Scanner(System.in);


System.out.println("Enter the number of grades: ");
double random = input.nextDouble();
double min = Integer.MIN_VALUE;
double max = Integer.MAX_VALUE;

double total=0;
int count = 1;
while (count < random+1) {




    System.out.println("Enter grade " + count + ":");

    double somenumber = input.nextDouble();
    total+=somenumber;

    count++;

    if (somenumber > max){
        max = somenumber;
    }
if (somenumber < min){
    min = somenumber;
}


}
System.out.println("Total is " + total);
System.out.println("Average is " + (total/random));
System.out.println("Largest number is " + max);
System.out.println("Smallest number is" + min);



        }

}

Largest number is 2.14748 Smallest number is -2.147478...That's what was printed...Am I making a arthimetic error?

Answer 4

Above while loop...

double max = 0;
double min = Double.MIN_VALUE;

In loop after you set some number...

if (someNumber > max){
  max = someNumber;
}
if (someNumber < min){
  min = someNumber;
}

Np glad it helped :) you should consider using a for loop instead of a while loop and declare someNumber outside of the loop like so:

double someNumber;
for (int i = 1; i <= random; i++){
  //...
}

To make it even cleaner you could replace i <= random in the for loop with

i <= readNumGrades(input);
private double  readNumGrades(Scanner in){
  System.out.println("Enter the number of grades");
  return in.nextDouble();
}

So you no longer need the variables count and random