Cara nggunakake metode entrySet () ing Jawa

Apa metode entrySet () ing Jawa?

Kelas HashMap nyedhiyakake metode java.util.HashMap.entrySet () ing Jawa. Iki digunakake kanggo nggawe banjur ngasilake 'set' saka unsur sing padha sing wis ana ing HashMap . Bisa digunakake kanthi daur ulang kanggo ngulang kabeh entri HashMap .

Metode Header

Header metode entrySet () diwenehi ing ngisor iki. Iki ngasilake tampilan set kabeh entri sing ngemot pasangan kunci-nilai. Kanggo nggunakake ing kode kita kudu ngimpor paket java.util.HashMap .

public Set<Map.Entry<key, value>> entrySet()

Paramèter

Cara entrySet () ora njupuk paramèter.

Jinis bali

Cara java.util.HashMap.entrySet () ngasilake conto saka set kelas.

Tuladha

import java.util.HashMap;

public class Driver1 {

	public static void main(String[] args) {

		// declare a custom hash map
		HashMap<Integer, String> hashMap = new HashMap<Integer, String>();

		// add data to the hash map
		hashMap.put(1, "Monday");
		hashMap.put(2, "Tuesday");
		hashMap.put(3, "Wednesday");
		hashMap.put(4, "Thursday");
		hashMap.put(5, "Friday");
		hashMap.put(6, "Saturday");
		hashMap.put(7, "Sunday");

		// print the original hash map
		System.out.println("Original HashMap: " + hashMap + '\n');
		// print the entrySet of the hash map
		System.out.println("HashMap.entrySet(): " + hashMap.entrySet() + '\n');

		// Try adding null value in the hash map
		hashMap.put(0, null);
		System.out.println("hashMap.put(0, null)");
		System.out.println("HashMap.entrySet(): " + hashMap.entrySet() + '\n');

		// Try adding null key and value pair to the hash map
		hashMap.put(null, null);
		System.out.println("hashMap.put(null, null)");
		System.out.println("HashMap.entrySet(): " + hashMap.entrySet() + '\n');

		// Try adding a null character as a value in the hash map 
		hashMap.put(null, "\0");
		System.out.println("hashMap.put(null, \"\\0\")");
		System.out.println("HashMap.entrySet(): " + hashMap.entrySet() + '\n');

	}
}

Output

Panjelasan

Ing cuplikan kode ing ndhuwur, kita wis ngimpor paket java.util.HashMap dhisik . Iki ngidini kita nggunakake metode HashMap lan entrySet () . Banjur nggawe hashMap sing dadi obyek saka kelas HashMap . HashMap kita ngemot strings minangka nilai. Tombol iku integer. Kita banjur ngisi hashMap . Ana pitung entri total. Kita banjur nggunakake setEntry () cara kanggo bali tampilan pesawat lan banjur print ing console.

Kesimpulan

Iki minangka implementasine prasaja saka metode Java HashMap entrySet() . Muga-muga sampeyan ngerti panggunaan metode kasebut sawise ngliwati kiriman iki. Kaya biasane, sampeyan dianjurake kanggo latihan bola-bali supaya bisa dadi apik. Nganti saiki, terus latihan lan terus berkembang!