Using arrays to find the largest number between 2 lists

Question

Create a program that randomly generates 5 numbers from 1 to 50, have these print out and then a second array to do the same thing. Have the program determine which is the largest number between the 2???? Okay so this is a question i asked myself and this is probably completely wrong but i tried: So this isn't exactly what i want but it's close. I would like it to show the actual highest number.

import java.util.*;
public class TwoArrays
{
public static void main (String args [] )
{
Random r = new Random();
int rangeMin = 0;
int rangeMax = 50;

ArrayList<Double> arrayList1 = new ArrayList<Double>();
ArrayList<Double> arrayList2 = new ArrayList<Double>();

for (int i =0;i<5;i++) 
{
    double randomValue = rangeMin + (rangeMax - rangeMin) * r.nextDouble();
    arrayList1.add(randomValue); 
}

for (int i =0;i<5;i++)  
{
    double randomValue = rangeMin + (rangeMax - rangeMin) * r.nextDouble();
    arrayList2.add(randomValue ); 
}


Double maxInArray1 = Collections.max(arrayList1);
Double maxInArray2 = Collections.max(arrayList2);

if (maxInArray1>maxInArray2)
{  
    System.out.println("first array have max");
}
else  if(maxInArray1<maxInArray2)
{
    System.out.println("second array have max");
}
else
{
    System.out.println("the max of second and first array is identical");

}
}
}

the largest number between the two lists or the largest total number of the two lists? — Blake Yarbrough, Sep 28 '15 at 18:17
Try using a variable to store the max value. When you assign `list[i] = (int)(Math.random() * 50) + 1; `, do a test, `if (list[i] > max) max = list[i]` — Johnny Willer, Sep 28 '15 at 18:17
possible duplicate of [Finding the max/min value in an array of primitives using Java](http://stackoverflow.com/questions/1484347/finding-the-max-min-value-in-an-array-of-primitives-using-java) — Johnny Willer, Sep 28 '15 at 18:18
Instead of building Arrays i woud recommend an Arraylist. Also to compare and sort your list you can use Collections.sort(comparator, List) — Tom Wellbrock, Sep 28 '15 at 18:22

score 1 · Answer 1 · edited Sep 28 '15 at 20:12

import java.util.*;
public class TwoArrays
{
public static void main (String args [] )
{
Random r = new Random();
int rangeMin = 0;
int rangeMax = 50;

ArrayList<Double> arrayList1 = new ArrayList<Double>();
ArrayList<Double> arrayList2 = new ArrayList<Double>();

for (int i =0;i<5;i++) 
{
    double randomValue = rangeMin + (rangeMax - rangeMin) * r.nextDouble();
    arrayList1.add(randomValue); 
}

for (int i =0;i<5;i++)  
{
    double randomValue = rangeMin + (rangeMax - rangeMin) * r.nextDouble();
    arrayList2.add(randomValue ); 
}


Double maxInArray1 = Collections.max(arrayList1);
Double maxInArray2 = Collections.max(arrayList2);

if (maxInArray1>maxInArray2)
{  
    System.out.println("first array have max");
}
else  if(maxInArray1<maxInArray2)
{
    System.out.println("second array have max");
}
else
{
    System.out.println("the max of second and first array is identical");

}
}
}

yep sounds reasonable :D at least if thats what the author of the question seeks :P — Tom Wellbrock, Sep 28 '15 at 18:26

Using arrays to find the largest number between 2 lists

1 Answers1