Java Collection Random Element selectRandom(Collection set)

Description

select Random

License

Apache License

Declaration

public static Object selectRandom(Collection<?> set) 

Method Source Code

//package com.java2s;
/* Copyright (c) 2015 University of Massachusetts
 * //from www.  ja va2 s  .c om
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License. */

import java.util.Collection;

import java.util.Iterator;

public class Main {
    public static Object selectRandom(Collection<?> set) {
        int random = (int) (Math.random() * set.size());
        Iterator<?> iterator = set.iterator();
        Object randomNode = null;
        for (int i = 0; i <= random && iterator.hasNext(); i++) {
            randomNode = iterator.next();
        }
        return randomNode;
    }
}

Related

1. randomElement(Collection coll)
2. randomElement(Collection in)
3. randomIterable(Collection col)
4. rndSubset(final Collection c, final double ratio)
5. sampleWithReplacement(Collection c, int n)
6. selectRandom(Collection col)
7. selectRandomSubset(Collection col, int count)
8. uniformSample(Collection set)