Loop to find max value

Question

Hi I'm having a problem to write a loop which finds the largest value.

A list of integers and an integer variable are declared like this: List list; int max;

Assuming that some values (including negatives!) have been added to the list. i need to find the largest value in list and stores it in max.

//  start of test code 
import java.util.*; 
public class ListTest 
{ 
private List<Integer> list; 
private int max;
public void findMaxInListTest()         { 
list = new ArrayList<Integer>(); // could be a Linked list 
list.add(0);
list.add(-99); 
list.add(99);
list.add(1320); 
list.add(470000); 
list.add(12);
list.add(-5000);
list.add(300);
/*#     max = starting value 
iterate through list to set max = max value in list 
in this case 470000     */ 
} 
}

I tried using this loop but then encounter an error:

int max = list[0];
  for(int i=470000;i < list.length;i++){
    if(list[i] > max){
      max = list[i];
    }
  }
return max;

do you know which kind of loop that appropriate for this? Thanks

Welcome to Stack overflow, and check the [syntax formatting possibilities](http://meta.stackoverflow.com/editing-help). — Ondra Žižka, May 31 '11 at 23:20
Hi Please see the answer here https://stackoverflow.com/questions/1484347/java-max-min-value-in-an-array — r0ast3d, May 31 '11 at 23:18

score 3 · Answer 1 · answered May 31 '11 at 23:14

3

You need to iterate over the list. Start with i=0 - not 47000.

Hope this helps.

answered May 31 '11 at 23:14

Adam Dymitruk

124,556
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score 2 · Answer 2 · answered May 31 '11 at 23:16

2

for(int i=470000;i < list.length;i++){

i is the index. put i=0. getting list element for index 470000 throws the exception.

also, list[i] doesn't work in java. use list.get(i). also, list.length doesn't work on lists. use list.size().

You're misinterpreting java List - it's not an array.

answered May 31 '11 at 23:16

Dariusz Jędrzejczyk

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also make max = list.get(0); so you initialize your max, if a number in the list is bigger than the first item,then you replace max with that. – Balazs Gunics Jun 27 '13 at 08:26

score 2 · Answer 3 · answered May 31 '11 at 23:59

2

import java.util.Collections;

Collections.sort(list);
System.out.println(list.get(list.size() - 1));

answered May 31 '11 at 23:59

Eder

1,874
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moeTi · Answer 4 · 2013-06-27T09:56:54.967

No loop required, use max method from java.utils.Collections (Documentation)

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Test {

    public static void main(String[] args) {

        List<Integer> list = new ArrayList<Integer>();
        list.add(0);
        list.add(-99);
        list.add(99);
        list.add(1320);
        list.add(470000);
        list.add(12);
        list.add(-5000);
        list.add(300);

        System.out.println(Collections.max(list));
    }
}

score 1 · Answer 5 · edited Jun 01 '11 at 12:41

1

for(int i=470000;i < list.length;i++){

should be

for(int i=0;i < list.length;i++){

edited Jun 01 '11 at 12:41

DarthJDG

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answered May 31 '11 at 23:15

Brad Johnson

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3

Loop to find max value

5 Answers5