Programming-Idioms

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New Java implementation by user [programming-idioms.org]

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2016-12-07, 21:45:11

2016-12-07, 21:59:28

Idiom #112 Iterate over map entries, ordered by keys

Print each key k with its value x from an associative array mymap, in ascending order of k.

Print each key k with its value x from an associative array mymap, in ascending order of k.

traverse traversal

traverse traversal

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

List<K> keys = new ArrayList<>(mymap.keySet());
Collections.sort(keys);
for(K k: keys)
	System.out.println("Key=" + k + ", Value=" + mymap.get(k));

Extract keys, sort, iterate.

Keys have type K.

https://docs.oracle.com/javase/7/docs/api/java/util/Collections.html#sort(java.util.List)

http://ideone.com/r0hpGp

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