Minimum element of an array

Question

I have, in Java, a double[] foo.

Is there a library function for pulling out the minimum value in this array? I know I can build one, but that's not a good practice if a library function is available. There's nothing in java.util.Arrays.

(In C++ we have std::min_element etc. and even a new function in C++11 to get the minimum and maximum out at the same time!)

It's not a good practice when it requires a lot of complicated code lines. That's not your case. Just implement a three easy lines solution. — Dmitry Bychenko, Oct 23 '14 at 12:13
Sadly not so. More than 3 lines once you've checked for null, zero length array etc. — P45 Imminent, Oct 23 '14 at 12:14

score 6 · Answer 1 · answered Oct 23 '14 at 12:18

6

Assuming Java 8:

double[] arr = { 1.0, 2.0 };
double min = DoubleStream.of(arr)
                         .min()
                         .getAsDouble();

answered Oct 23 '14 at 12:18

McDowell

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+1, pretty (and is the best answer to my question given that Java 8 is the current standard and I tagged as Java) but don't have Java 8 yet. – P45 Imminent Oct 23 '14 at 12:33

score 4 · Accepted Answer · answered Oct 23 '14 at 12:15

4

Well, Collections class has such method.

You can write

Double[] arr = {0.5,0.7};
System.out.println("min = " + Collections.min(Arrays.asList(arr)));

Or to make it shorter :

System.out.println("min = " + Collections.min(Arrays.asList(-67,-89,64,34)));

answered Oct 23 '14 at 12:15

Eran

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+1 but have reservations about converting `double[]` to `Double[]` – P45 Imminent Oct 23 '14 at 12:17
1

@SlodgeMonster Arrays.asList on a double array will return a List with a single double[] element, so you must use Double array. – Eran Oct 23 '14 at 12:20
Thanks, I went for this in the end having changed my `double[]` to a `Double[]`. `Collections.min(Arrays.asList(arr))` is standard Java and doesn't take a deep copy. – P45 Imminent Oct 23 '14 at 12:32

Alex · Answer 3 · 2014-10-23T12:23:16.107

1

You can convert double[] to Double[] using ArrayUtils.toObject.
Then convert array to list with Arrays.asList and find minimum with Collections.min.

double[] d = new double[] {1, 2, 3};
Double minValue = Collections.min(Arrays.asList(ArrayUtils.toObject(d)));
System.out.println(minValue);

edited Oct 23 '14 at 12:23

answered Oct 23 '14 at 12:17

Alex

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akash · Answer 4 · 2014-10-23T12:36:28.267

1

You can use com.google.common.primitives.Doubles

 double[] arr = { 4.3, 4.9 };
 double min = Doubles.min(arr);
 //OR
 //double min = Doubles.min(4.3, 4.9);

edited Oct 23 '14 at 12:36

answered Oct 23 '14 at 12:25

akash

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Minimum element of an array

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