Java Learning Note 28

Vector is the implementation class of the list interface, supports all functions of the list interface, the vector class is an array-based implementation of the list class, in the internal encapsulation of a dynamic,

Allow redistribution of the object[] array, vector is thread-safe, without the need for a program to ensure the synchronization of the collection.

The following is a description of the methods used by the vector class:

public class Main {public static void main (string[] args) {vector vector = new vector (); Vector.add ("BILL"); Vector.add ("JAC K ");//output: [BILL, Jack]system.out.println (vector);//output: Vector Capacity: 10system.out.println (" vector Volume: "+ vector.capacity ( ); */* Sets the size of this vector. If the new size is greater than the current size, the corresponding number of NULL entries is added at the end of the vector. If the new size is less than the current size, all items at index * newSize and beyond are discarded. If the new size is negative, throw ArrayIndexOutOfBoundsException exception */vector.setsize (21);//output: Vector Capacity: 21system.out.println ("Vector Volume:" + vector.capacity ());/* Returns the capacity of this vector */system.out.println (vector.size ());//output: 21/* * Returns a partial view of this List, with elements ranging from fromIndex (including) to Toindex (not included). (If FromIndex and * toindex are equal, the returned List will be empty). The returned list is supported by this list, so the changes returned in the list are reflected in this * list, and vice versa. The returned list supports all optional list operations supported by this list. */list List = (list) vector.sublist (0, 1);//output: [Bill]system.out.println (List.tostring ());/* * Returns an array, Contains all the elements in this vector that are stored in the proper order. */object[] obj = (object[]) Vector.toarray ();//output: BILL JAC null NULL NULL NULL NULL NULL//NULL NULL NULL NULL NULL NULL NULL null//NULL NULL NULL nullfor (Object ob:oBJ) {System.out.println (OB);} Vector.setsize (5);//Set the vector capacity to 5string[] str = new string[6];/* * Returns an array containing all the elements in the proper order of this vector; the run-time type of the returned array is the type of the specified array. If the vector adapts to the specified array, the array is returned. * Otherwise, a new array is allocated using the run-time type of this array and the size of this vector. Note: When the size of the returned array is less than the capacity of the vector, the returned array is null; * When the size of the returned array is equal to the capacity of the vector, the vector elements are placed in the array, and if the size of the returned array is larger than the capacity of the vector, the vector elements are placed in the array, and the remaining positions */vector.toarray (str);//output: [BILL, JACK, NULL, NULL, NULL, NULL]SYSTEM.OUT.PRINTLN (arrays.tostring (str));/* * Returns a string representation of this vector that contains a string representation of each element. *///output: [BILL, JACK, NULL, NULL, NULL]SYSTEM.OUT.PRINTLN (vector.tostring ());/* fine-tune the capacity of this vector so that it is equal to the current size of the vector. */vector.trimtosize ();//output: 5system.out.println (Vector.capacity ());/* * This vector specifies the component at index to the specified object. Discards the previous component of the location. If the index is out of range (Index < 0 | | Index >= * SIZE ()), throw arrayindexoutofboundsexception exception */vector.setelementat ("Marry", 3);//Output Out: [BILL, JACK, NULL, Marry, null]system.out.println (vector); */* Replace the element at the specified position in this vector with the specified element. If the index is out of range (Index < 0 | | index >= SIZE ()) * Throws ArrayIndexOutOfBoundsException exception */vector.set (3, "change");//output: [BILL, JACK, NULL, change, null]system.out.println (vector),/* * Remove all components from this vector and set their size to zero. */vector.removeallelements (); System.out.println (Vector.size ());//Output 0}}

Reprint Please specify source: http://blog.csdn.net/hai_qing_xu_kong/article/details/44119233 Emotional Control _ 

Java Learning Note 28