Finding the largest number in an array

Question

I'm trying to figure how to find the largest number in an array of random numbers.

So far I cant manage to get it right.

Its an array[50] and the random, numbers are between 0-100.

Thanks!

`So far I cant manage to get it right.` Then what are you getting wrong? — Sotirios Delimanolis, Dec 26 '13 at 19:39
Conceptually, how would you do find the largest number in an array (list, or set)? — Sotirios Delimanolis, Dec 26 '13 at 19:39
Thats the problem , I cant find the logic to startt , beside etting the random numbers , and the length of the array , I'm pretty much blacked out. — RanTz, Dec 26 '13 at 19:42
Say you had ten balls of the same size, but of different weights. What would you do to find the heaviest? — Sotirios Delimanolis, Dec 26 '13 at 19:43
This has already been answered on SO http://stackoverflow.com/a/1806830/265877 — Alex, Dec 26 '13 at 19:45
I'll weight each one and compare them to find the heaviest. Edit: thanks alex — RanTz, Dec 26 '13 at 19:46
So using that analogy with arrays, how would you get the _weight_ (the value) of each element? How would you compare it? — Sotirios Delimanolis, Dec 26 '13 at 19:47

score 7 · Answer 1 · answered Dec 26 '13 at 19:42

7

Loop through the array and keep track of the largest number found already in an int variable.

answered Dec 26 '13 at 19:42

Martin Dinov

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score 1 · Answer 2 · answered Dec 26 '13 at 19:45

1

public int findMax(int[] numbers)
{
    int max = 0;

    for (int i = 0; i < numbers.length; ++i)
        if (numbers[i] > max) max = numbers[i];

    return max;
}

(You can also initialize max to int.MIN_VALUE or something if it helps behave more suitably in the case where an empty array is passed in.)

answered Dec 26 '13 at 19:45

TypeIA

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Would the downvoter please comment? Thanks. – TypeIA Dec 26 '13 at 19:50
You've deprived the OP of any learning opportunity. Better would be to help the OP arrive at this solution himself. – dnault Dec 26 '13 at 19:50
1

@dnault Learning opportunities are up to him, not me. Personally I find studying example code extremely useful and informative when I'm trying to learn something new. If he just pastes in the answer and moves on, he made that choice, not me. – TypeIA Dec 26 '13 at 19:54
Fair point about learning from example code. Please have your vote back along with my apologies. – dnault Dec 26 '13 at 20:14

score 0 · Answer 3 · answered Dec 26 '13 at 19:48

0

Use:

java.utils.Arrays.sort(yours_array);
int largest = yours_array[yours_array.length - 1] ;

answered Dec 26 '13 at 19:48

Vyacheslav Shylkin

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@user2966293 don't do this. see my comments in Hammam's solution as to why. This is essentially the same thing. – user2910265 Dec 26 '13 at 19:59
and since Hammam deleted his answer, I'll post it here. It's inefficient, it modifies the original array. – user2910265 Dec 26 '13 at 20:29

score 0 · Answer 4 · answered Dec 26 '13 at 19:49

0

Collections.max and you can use it as follows with a raw array:

List<Integer> triedArray = new ArrayList<Integer>();
ArrayUtils.addAll(intArray);

This does add a dependency on commons-lang, though.

answered Dec 26 '13 at 19:49

hd1

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score 0 · Answer 5 · answered Dec 26 '13 at 19:50

Assuming the int[] is named array

Try to use a loop like the following:

int biggest = array[0]
for(int a = 1; a < array.length; a++){
    if(array[a] > biggest){
        biggest = array[a]
    }
}

At the end, your variable biggest will hold the largest value in the array.

Finding the largest number in an array

5 Answers5