Metode HashMap getOrDefault ing Jawa

Apa metode getOrDefault kanggo HashMaps ing Jawa?

" Cara getOrDefault ngasilake nilai sing dipetakan menyang kunci sing ditemtokake ing HashMap . Yen kunci kasebut ora ana, nilai standar bakal dibalekake. Kelas java.util.HashMap nerangake karo cara getOrDefault kanggo menehi hak istimewa ekstra maringaken Nilai standar. Nilai standar bisa digunakake kanggo macem-macem tujuan ing macem-macem kahanan. Panggunaan lan mbandhingake karo metode entuk sing gampang bakal diterangake mengko ing kirim.

Apa header kanggo metode getOrDefault ()?

Header biasa kanggo metode getOrDefault ditetepake kaya ing ngisor iki.

hashMap.getOrDefault(Object key, Object defaultValue)

Parameter Lulus

Header metode njupuk rong argumen. Dheweke didaftar bebarengan karo jinis data ing ngisor iki.

1. Sing pisanan yaiku kunci sing ditemtokake saka jinis Obyek.
2. Tipe Obyek liyane yaiku parameter defaultValue sing dilewati kanggo tombol obyek minangka argumen metode.

Nggarap metode getOrDefault().

Sampeyan bisa ngerti cara kerja getOrDefault () ing rong langkah prasaja ing ngisor iki.

1. GetOrDefault (key, defaultValue) dirancang kanggo entuk nilai sing cocog karo kunci ing HashMap .
2. Yen ana nilai sing ana gandhengane karo kunci kasebut, nilai kasebut bakal bali. Ing tangan liyane, yen nilai ora kasedhiya, banjur defaultValue liwati minangka parameter kanggo cara iki bali.

Tuladha 1

import java.util.HashMap;

public class Driver1{

	public static void main(String[] args) {

		// Declare a HashMap
		HashMap weekDays = new HashMap<>();

		// Add data to the HashMap
        weekDays.put("Monday", "Working Day");
        weekDays.put("Tuesday", "Working Day");
        weekDays.put("Wednesday", "Working Day");
        weekDays.put("Thursday", "Working Day");
        weekDays.put("Friday", "Working Day");
        weekDays.put("Saturday", "Off Day");
        weekDays.put("Sunday", "Off Day");

        // Print the data in the HashMap
        System.out.println("Working Schedule : " + weekDays + "\n");


        // Check if the given key is present in the Map
        // IF yes, its value will be returned
        String sunday = weekDays.getOrDefault("Sunday", "No Announcements Yet.");
        System.out.println("Is Sunday a working day?  " + sunday);

        // IF not, the default value passed will be returned
        String christmas = weekDays.getOrDefault("Christmas", "National Holiday");
        System.out.println("Is Christmas a working day?  " + christmas);

        // Key not present in the HashMap
        // Default Value returned
        String easter = weekDays.getOrDefault("Easter", "National Holiday");
        System.out.println("Is Easter a working day?  " + easter);
	}

}

Output

Napa nggunakake metode getOrDefault () lan ora entuk ()?

Cara njaluk () prasaja ing Jawa digunakake kanggo entuk nilai kunci sing dijaluk ing HashMap . Yen kunci ditemokake, nilai kasebut bali. Yen kunci ora ditemokake, "null" bali. Metode getOrDefault () luwih disenengi tinimbang metode get sing gampang nalika nilai standar bakal bali. Punika conto prasaja kanggo pangerten.

Tuladha 2

import java.util.HashMap;
public class Driver2{

	public static void main(String[] args) {

	  HashMap<Object, Boolean> holidays = new HashMap<>();

	  // Add data to the HashMap
        holidays.put("Saturday",  true);
        holidays.put("Sunday", true);

        // Print the data in the HashMap
        System.out.println("Holidays: " + holidays + "\n");

        // Key not present, default value returned
        Object christmas = holidays.getOrDefault("Christmas", true);
        System.out.println("Is Christmas a holiday?  " + christmas);

        // Key not present, null returned
        christmas = holidays.get("Christmas");
        System.out.println("Is Christmas a holiday?  " + christmas);
	}
}

Output

Sampeyan bisa ndeleng prabédan antarane getOrDefault lan cara njaluk . Minangka dicithak ing output, cara pisanan ngasilake nilai standar yen tombol ora ditemokake nalika sing terakhir bali null.

Kesimpulan

Ing pungkasan kiriman iki, sampeyan kudu ngerti metode getOrDefault () HashMap . Sampeyan disaranake sinau kanthi latihan. Aja bebas mriksa kiriman iki maneh yen sampeyan macet ing dalan. Nganti saiki, terus latihan lan terus berkembang!