[eagleuk]

Hi there!

I would like to know how could I read data from a file. I have got something like that:

1 10
2 25
3 40
4 25
5 24
6 25
7 25
8 41
9 55
10 11
11 54
12 20

where numbers from 1-12 are actually months, which I have to convert to a String.

At the moment my program is reading all those integers, but I need to make it to read only second column for counting averages...

So far my code:

 

import java.util.*;
import java.io.*;

class Exercise{
	public static void main(String[] args)throws Exception{
		ArrayList<Integer> store = new ArrayList<Integer>();
		
		String FileName;
		int total = 0;
		int number = 0;
		
		Scanner scanner = new Scanner(System.in);
		System.out.println("Please type in the name of your file: ");
		FileName = scanner.nextLine();
		
		File inputFile = new File(FileName);
		Scanner reader = new Scanner(inputFile);
		
		
		while(reader.hasNext()){
			int numbers = reader.nextInt();
			store.add(numbers);
			System.out.println(numbers);
		}
		Iterator<Integer> myIterator = store.iterator();
		
		while(myIterator.hasNext()){
			number = myIterator.next();
			total = total + number;
		}
		
		System.out.println("The total rainfall for this year is: " + total);
		int average = ((total)/12);
		
		System.out.println("The average of monthly rainfall is: " + average); 

Many thanks for any help!

[pbl]

not complicated at all
you already read one just read the second

int numbers = reader.nextInt();
int secondNumber = reader.nextInt();

[eagleuk]

pbl, on 5 Nov, 2008 - 07:45 PM, said:

not complicated at all
you already read one just read the second

int numbers = reader.nextInt();
int secondNumber = reader.nextInt();

Ok I have done this. I did not know that it could be so easy, do you know how to find from my SecondNumbers minimum and maximum value? I tried sth like that:

 		while(myIterator.hasNext()){
			number = myIterator.next();
		}
  
		int min = (int) Collections.min(Arrays.asList(number));
		int max = (int) Collections.max(Arrays.asList(number));
		
		System.out.println("Min number: " + min);
		System.out.println("Max number: " + max); 

many thanks

[eagleuk]

 import java.util.*;
import java.io.*;



public class Assignment5{
	public static void main(String[] args)throws Exception{
		ArrayList<Integer> store = new ArrayList<Integer>();
		
		String FileName;
		int total = 0;
		int number = 0;
			
		Scanner scanner = new Scanner(System.in);
		System.out.println("Please type in the name of your file: ");
		FileName = scanner.nextLine();
		
		File inputFile = new File(FileName);
		Scanner reader = new Scanner(inputFile);
		
		
		while(reader.hasNext()){
			int numbers = reader.nextInt();
			int secondNumbers = reader.nextInt(); //This command reads second values from our file;
			store.add(secondNumbers);
			
		}
		Iterator<Integer> myIterator = store.iterator();
		
		
		
		while(myIterator.hasNext()){
			number = myIterator.next();
			total = total + number;
		}
		
		System.out.println("The total rainfall for this year is: " + total);
		int average = ((total)/12);
		
		System.out.println("The average of monthly rainfall is: " + average);
		
		while(myIterator.hasNext()){
			number = myIterator.next();
		}
  
int min = (int) Collections.min(Arrays.asList(number));
		int max = (int) Collections.max(Arrays.asList(number));
		
		System.out.println("Min number: " + min);
		System.out.println("Max number: " + max);
	
}
		
				
	}  

This program does do everything correctly, but I do not know why it prints max and min value as my last integer from my ArrayList


BTW input (my file has this data) :

1 10
2 25
3 40
4 25
5 24
6 25
7 25
8 41
9 55
10 11
11 54
12 20

any solutions?

[Locke]

I, myself, would just loop through the entire ArrayList and find the max/min values.

int min = store.get(0);
int max = store.get(0);

for (int x = 1; x < store.size(); x++) // loop thru all
{
    // comparisons
    if (store.get(x) < min)
    {
        min = store.get(x);
        continue;
    }

    if (store.get(x) > max)
        max = store.get(x);
}

System.out.println("Min number: " + min);
System.out.println("Max number: " + max);

Hope this helps!

This post has been edited by Locke37: 06 November 2008 - 06:48 PM

[eagleuk]

It doesn't work or I do not how to do it:/ Why my previous version does not work correctly? How to solve it? i am a noob!

[pbl]

or easier:

int min = +99999999;
int max = -99999999;

read you data
and
if(value < min)
min = value;
if(value > max)
max = value;

....

[Locke]

To be honest, I don't know why your version doesn't work. I've never used an Iterator before, so I'm unfamiliar with how it does things.

I know that mine will work though.

[Locke]

There's a duplicate thread...

This post has been edited by Locke37: 06 November 2008 - 06:53 PM

[eagleuk]

I have to use Iterator in my exercise ;/

[Locke]

Oh...well nevermind me then. I could look it up...but by that time, pbl will probably have given you a solution.

[BigAnt]

change:

int min = (int) Collections.min(Arrays.asList(number));
int max = (int) Collections.max(Arrays.asList(number));

to:

int min = (int) Collections.min(store);
int max = (int) Collections.max(store);

[pbl]

Locke37, on 6 Nov, 2008 - 05:49 PM, said:

There's a duplicate thread...

Merge done
Thanks Locke37

By the way is the "37" means that you were born in 1937 ?

[eagleuk]

ok, it works

but if it is a possible how to make it to print out which value it was (e.g. The minimum was in the 3 row - and the 3rd row means March)

[pbl]

pbl, on 6 Nov, 2008 - 05:45 PM, said:

or easier:

int min = +99999999;
int max = -99999999;
int monthMin, montMax;

read you data
and

if(value < min) {
   min = value;
   monthMin = month;
}

if(value > max) {
   max = value;
   monthMax = month;
}

....