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Vektor je poput dinamički niz koji može rasti ili smanjivati ​​svoju veličinu. Za razliku od polja, u njega možemo pohraniti n-broj elemenata jer nema ograničenja veličine. Dio je okvira Java Collection od Jave 1.2. Nalazi se ujava.utilpakirati i implementirati Popis sučelje, tako da ovdje možemo koristiti sve metode sučelja List.

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Preporuča se koristiti klasu Vector samo u niti sigurnoj implementaciji. Ako ne trebate koristiti niti sigurnu implementaciju, trebali biste koristiti ArrayList, ArrayList će u tom slučaju raditi bolje.

Iteratori koje vraća klasa Vector su fail-fast . U slučaju istodobne izmjene, ne uspijeva i izbacuje ConcurrentModificationException.

Sličan je ArrayList-u, ali s dvije razlike-

• Vektor je sinkroniziran.
• Java Vector sadrži mnogo naslijeđenih metoda koje nisu dio okvira zbirki.

Deklaracija klase Java Vector

 public class Vector extends Object implements List, Cloneable, Serializable 

Java vektorski konstruktori

Vektorska klasa podržava četiri vrste konstruktora. One su navedene u nastavku:

Java vektorske metode

Slijedi popis metoda klase Vector:

instanca jave

Primjer Java vektora

 import java.util.*; public class VectorExample { public static void main(String args[]) { //Create a vector Vector vec = new Vector(); //Adding elements using add() method of List vec.add('Tiger'); vec.add('Lion'); vec.add('Dog'); vec.add('Elephant'); //Adding elements using addElement() method of Vector vec.addElement('Rat'); vec.addElement('Cat'); vec.addElement('Deer'); System.out.println('Elements are: '+vec); } } 

Izlaz:

 Elements are: [Tiger, Lion, Dog, Elephant, Rat, Cat, Deer] 

Primjer Java vektora 2

 import java.util.*; public class VectorExample1 { public static void main(String args[]) { //Create an empty vector with initial capacity 4 Vector vec = new Vector(4); //Adding elements to a vector vec.add('Tiger'); vec.add('Lion'); vec.add('Dog'); vec.add('Elephant'); //Check size and capacity System.out.println('Size is: '+vec.size()); System.out.println('Default capacity is: '+vec.capacity()); //Display Vector elements System.out.println('Vector element is: '+vec); vec.addElement('Rat'); vec.addElement('Cat'); vec.addElement('Deer'); //Again check size and capacity after two insertions System.out.println('Size after addition: '+vec.size()); System.out.println('Capacity after addition is: '+vec.capacity()); //Display Vector elements again System.out.println('Elements are: '+vec); //Checking if Tiger is present or not in this vector if(vec.contains('Tiger')) { System.out.println('Tiger is present at the index ' +vec.indexOf('Tiger')); } else { System.out.println('Tiger is not present in the list.'); } //Get the first element System.out.println('The first animal of the vector is = '+vec.firstElement()); //Get the last element System.out.println('The last animal of the vector is = '+vec.lastElement()); } } 

Izlaz:

što je mapa java

 Size is: 4 Default capacity is: 4 Vector element is: [Tiger, Lion, Dog, Elephant] Size after addition: 7 Capacity after addition is: 8 Elements are: [Tiger, Lion, Dog, Elephant, Rat, Cat, Deer] Tiger is present at the index 0 The first animal of the vector is = Tiger The last animal of the vector is = Deer 

Primjer Java vektora 3

 import java.util.*; public class VectorExample2 { public static void main(String args[]) { //Create an empty Vector Vector in = new Vector(); //Add elements in the vector in.add(100); in.add(200); in.add(300); in.add(200); in.add(400); in.add(500); in.add(600); in.add(700); //Display the vector elements System.out.println('Values in vector: ' +in); //use remove() method to delete the first occurence of an element System.out.println('Remove first occourence of element 200: '+in.remove((Integer)200)); //Display the vector elements afre remove() method System.out.println('Values in vector: ' +in); //Remove the element at index 4 System.out.println('Remove element at index 4: ' +in.remove(4)); System.out.println('New Value list in vector: ' +in); //Remove an element in.removeElementAt(5); //Checking vector and displays the element System.out.println('Vector element after removal: ' +in); //Get the hashcode for this vector System.out.println('Hash code of this vector = '+in.hashCode()); //Get the element at specified index System.out.println('Element at index 1 is = '+in.get(1)); } } 

Izlaz:

 Values in vector: [100, 200, 300, 200, 400, 500, 600, 700] Remove first occourence of element 200: true Values in vector: [100, 300, 200, 400, 500, 600, 700] Remove element at index 4: 500 New Value list in vector: [100, 300, 200, 400, 600, 700] Vector element after removal: [100, 300, 200, 400, 600] Hash code of this vector = 130123751 Element at index 1 is = 300