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How to print a collection in Java
Problem Description
How to print a collection?
Solution
Following example how to print a collection by using tMap.keySet(), tMap.values() and tMap.firstKey() methods of Java Util class.
import java.util.*; public class TreeExample{ public static void main(String[] args) { System.out.println("Tree Map Example!\n"); TreeMap <Integer, String>tMap = new TreeMap<Integer, String>(); tMap.put(1, "Sunday"); tMap.put(2, "Monday"); tMap.put(3, "Tuesday"); tMap.put(4, "Wednesday"); tMap.put(5, "Thursday"); tMap.put(6, "Friday"); tMap.put(7, "Saturday"); System.out.println("Keys of tree map: " + tMap.keySet()); System.out.println("Values of tree map: " + tMap.values()); System.out.println("Key: 5 value: " + tMap.get(5)+ "\n"); System.out.println( "First key: " + tMap.firstKey() + " Value: " + tMap.get(tMap.firstKey()) + "\n"); System.out.println( "Last key: " + tMap.lastKey() + " Value: "+ tMap.get(tMap.lastKey()) + "\n"); System.out.println("Removing first data: " + tMap.remove(tMap.firstKey())); System.out.println("Now the tree map Keys: " + tMap.keySet()); System.out.println("Now the tree map contain: " + tMap.values() + "\n"); System.out.println("Removing last data: " + tMap.remove(tMap.lastKey())); System.out.println("Now the tree map Keys: " + tMap.keySet()); System.out.println("Now the tree map contain: " + tMap.values()); } }
Result
The above code sample will produce the following result.
C:\collection>javac TreeExample.java C:\collection>java TreeExample Tree Map Example! Keys of tree map: [1, 2, 3, 4, 5, 6, 7] Values of tree map: [Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday] Key: 5 value: Thursday First key: 1 Value: Sunday Last key: 7 Value: Saturday Removing first data: Sunday Now the tree map Keys: [2, 3, 4, 5, 6, 7] Now the tree map contain: [Monday, Tuesday, Wednesday, Thursday, Friday, Saturday] Removing last data: Saturday Now the tree map Keys: [2, 3, 4, 5, 6] Now the tree map contain: [Monday, Tuesday, Wednesday, Thursday, Friday] C:\collection>
java_collections.htm
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