We have already discussed ArrayLists and\u00a0 LinkedList. We also discussed difference between ArrayList and Lists in Java.<\/p>\n
I suggest you review them:<\/p>\n
<\/p>\n
However, today, we would learn about Vectors. You use the Vector class to implement a dynamic array in Java. Similar to ArrayLists, Vectors also derives from the List class.<\/p>\n
But unlike ArrayLists:<\/p>\n
<\/p>\n
How to Create a vector<\/strong><\/p>\n Similar to how you create an ArrayList, you can also create a vector using its constructor. Example is given below.<\/p>\n The first line creates a vector of objects while the second line creates a vector of Strings.<\/p>\n <\/p>\n You can as well use any of the constructor listed below<\/p>\n Creates a vector of initial size of 10. The default data type is object. We already used this<\/td>\n<\/tr>\n Accepts a parameter of the\u00a0 initial size of the vector . Then creates a vector whose initial capacity is the given size<\/td>\n<\/tr>\n Creates a vector whose initial capacity is specified by size and whose increment is specified by incr. The increment specifies number of elements to allocate any time the\u00a0 vector is resized upward.<\/td>\n<\/tr>\n This constructor creates a vector from\u00a0 the elements of collection c. So the elements of the collection would be transferred to the new vector.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n <\/p>\n The program below creates a vector of Strings, vector2. <\/p>\n I would then provide a list of methods available in a vector class. You can therefore use these methods to perform any kind of operations on a vector.<\/p>\n Inserts the specified element at the position(given by index) in this Vector.<\/td>\n<\/tr>\n Adds an\u00a0 element to the end of the Vector.<\/td>\n<\/tr>\n Copies all of the elements in the given Collection to the end of this Vector, in the order that they are returned by the given Collection’s Iterator.<\/td>\n<\/tr>\n Copies all of the elements in in the given Collection c, into the Vector at the specified index.<\/td>\n<\/tr>\n Adds the specified component to the end of this vector, increasing its size of the vector by one.<\/td>\n<\/tr>\n You use this to get the capacity of the Vector<\/td>\n<\/tr>\n Deletes all of the elements of the vector.<\/td>\n<\/tr>\n Returns a clone of the vector as an object<\/td>\n<\/tr>\n Checks if the given object is an element in the vector.<\/td>\n<\/tr>\n Checks if the vector contains all of the elements in the given Collection. Returns true if yes. Otherwise, returns false.<\/td>\n<\/tr>\n Copies the elements of this vector into the given array.<\/td>\n<\/tr>\n Returns the element at the given index.<\/td>\n<\/tr>\n Used to returns an enumeration of the elements of the vector.<\/td>\n<\/tr>\n Used to increase the capacity of the vector to the capacity specified by minCapacity<\/td>\n<\/tr>\n Uses to check is the vector and the spefied object are equal<\/td>\n<\/tr>\n Used to return the first component (the item at index 0) of this vector.<\/td>\n<\/tr>\n Used to return the element at the specified position in this vector.<\/td>\n<\/tr>\n Used to return the hash code value for this vector.<\/td>\n<\/tr>\n Searches for the first occurrence of the specified parameter, checking for equality using the equals method.<\/td>\n<\/tr>\n Searches for the first occurrence of the specified parameter, beginning at index, and checking for equality using the equals method.<\/td>\n<\/tr>\n Inserts the given object as a component in this vector at the given index.<\/td>\n<\/tr>\n Checks if this vector is empty. Returns true if the vector is empty. Returns false if othewise<\/td>\n<\/tr>\n Used to return to return\u00a0 the last element of the vector.<\/td>\n<\/tr>\n Used to return the index of the last occurrence of the specified object in the vector.<\/td>\n<\/tr>\n Searches backwards for the given object, beginning at the specified index, and returns an index the element.<\/td>\n<\/tr>\n Removes the particular element at the specified index in the vector.<\/td>\n<\/tr>\n Removes the first occurrence of the given element from\u00a0 the vector, If the vector does not contain the element, it is unchanged.<\/td>\n<\/tr>\n Removes from this vector all of its elements that are contained in the given Collection<\/td>\n<\/tr>\n Takes out all of the\u00a0 elements\u00a0 of this vector and sets its size to zero.<\/td>\n<\/tr>\n Removes the first occurrence of the specified\u00a0 argument from this vector.<\/td>\n<\/tr>\n Removes element at the given index from the Vector<\/td>\n<\/tr>\n Removes all of the elements in the vector\u00a0 from fromIndex, inclusive and toIndex, exclusive.<\/td>\n<\/tr>\n Retains only the elements in this vector that are contained in the given Collection.<\/td>\n<\/tr>\n Use this to replace the element at the specified position in the vector with the specified element.<\/td>\n<\/tr>\n Sets the element at the specified index of the vector to be the given object.<\/td>\n<\/tr>\n Sets the size of the vector to the newSize<\/td>\n<\/tr>\n Used to return\u00a0 the number of components in this vector.<\/td>\n<\/tr>\n Used to return\u00a0 a\u00a0 subList of the vector between fromIndex, inclusive, and toIndex, exclusive.<\/td>\n<\/tr>\n Used to return\u00a0 an object array containing all of the items in the vector in the correct order.<\/td>\n<\/tr>\n Used to return an object array containing all of the item in the vector in the correct order; the runtime type of the returned array is that of the given array.<\/td>\n<\/tr>\n Used to return\u00a0 a string representation of the vector, containing the String representation of each of the element.<\/td>\n<\/tr>\n Reduces the capacity of this vector down to\u00a0 the vector’s current size.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Table 1.1: Methods in the Vector Class<\/p>\n <\/p>\n Below is a program that illustrates how to use some of the methods listed above. I recommend you run this code yourself. Also try\u00a0 to use other methods to see how they work.<\/p>\n <\/p>\n Program to demonstrate use or Vector Methods<\/p>\n","protected":false},"excerpt":{"rendered":" We have already discussed ArrayLists and\u00a0 LinkedList. We also discussed difference between ArrayList and Lists in Java. I suggest you review them: ArrayList and LinkedList … <\/p>\n","protected":false},"author":395,"featured_media":165,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[2],"tags":[],"class_list":["post-163","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java-tutorial"],"_links":{"self":[{"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/posts\/163","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/users\/395"}],"replies":[{"embeddable":true,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/comments?post=163"}],"version-history":[{"count":7,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/posts\/163\/revisions"}],"predecessor-version":[{"id":214,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/posts\/163\/revisions\/214"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/media\/165"}],"wp:attachment":[{"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/media?parent=163"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/categories?post=163"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/tags?post=163"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\tVector vector1 =<\/span> new<\/span> Vector();<\/span>\r\n\tVector<<\/span>String><\/span> vector2 =<\/span> new<\/span> Vector<<\/span>String>();<\/span>\t\t\r\n<\/pre>\n\n\n
\n SN<\/th>\n Constructor and brief description<\/th>\n<\/tr>\n \n 1.<\/td>\n Vector( )<\/b><\/p>\n \n 2<\/td>\n Vector(int size)<\/b><\/p>\n \n 3<\/td>\n Vector(int size, int incr)<\/b><\/p>\n \n 4<\/td>\n Vector(Collection c)<\/b><\/p>\n
\nThen uses the add() method to add 3 strings to the vector
\nFinally uses an enhanced for loop to print out the elements of the vector<\/p>\nimport<\/span> java.util.Vector<\/span>;<\/span>\r\n\r\npublic<\/span> class<\/span> VectorDemo<\/span> {<\/span>\r\n\r\n public<\/span> static<\/span> void<\/span> main<\/span>(<\/span>String[]<\/span> args)<\/span> {<\/span>\r\n\r\n\tVector<<\/span>String><\/span> vector2 =<\/span> new<\/span> Vector<<\/span>String>();<\/span>\t\r\n\tvector2.<\/span>add<\/span>(<\/span>\"Kindson\"<\/span>);<\/span>\r\n\tvector2.<\/span>add<\/span>(<\/span>\"Saffon\"<\/span>);<\/span>\r\n\tvector2.<\/span>add<\/span>(<\/span>\"Oleander\"<\/span>);<\/span>\r\n\t\t\r\n\tfor<\/span> (<\/span>String element :<\/span>vector2)<\/span> {<\/span>\r\n\t\tSystem.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>element);<\/span>\r\n\t}<\/span>\r\n\r\n }<\/span>\r\n}<\/span>\r\n\t\r\n<\/pre>\n\n\n
\n SN.<\/th>\n Method and brief description<\/th>\n<\/tr>\n \n 1<\/td>\n add(int index, Object element)<\/b><\/p>\n \n 2<\/td>\n add(Object o)<\/b><\/p>\n \n 3<\/td>\n boolean addAll(Collection c)<\/b><\/p>\n \n 4<\/td>\n addAll(int index, Collection c)<\/b><\/p>\n \n 5<\/td>\n addElement(Object obj)<\/b><\/p>\n \n 6<\/td>\n int capacity()<\/b><\/p>\n \n 7<\/td>\n clear()<\/b><\/p>\n \n 8<\/td>\n clone()<\/b><\/p>\n \n 9<\/td>\n contains(Object elem)<\/b><\/p>\n \n 10<\/td>\n containsAll(Collection c)<\/b><\/p>\n \n 11<\/td>\n copyInto(Object[] anArray)<\/b><\/p>\n \n 12<\/td>\n elementAt(int index)<\/b><\/p>\n \n 13<\/td>\n Enumeration elements()<\/b><\/p>\n \n 14<\/td>\n ensureCapacity(int minCapacity)<\/b><\/p>\n \n 15<\/td>\n equals(Object o)<\/b><\/p>\n \n 16<\/td>\n firstElement()<\/b><\/p>\n \n 17<\/td>\n get(int index)<\/b><\/p>\n \n 18<\/td>\n hashCode()<\/b><\/p>\n \n 19<\/td>\n indexOf(Object elem)<\/b><\/p>\n \n 20<\/td>\n indexOf(Object elem, int index)<\/b><\/p>\n \n 21<\/td>\n insertElementAt(Object obj, int index)<\/b><\/p>\n \n 22<\/td>\n isEmpty()<\/b><\/p>\n \n 23<\/td>\n lastElement()<\/b><\/p>\n \n 24<\/td>\n lastIndexOf(Object elem)<\/b><\/p>\n \n 25<\/td>\n lastIndexOf(Object elem, int index)<\/b><\/p>\n \n 26<\/td>\n remove(int index)<\/b><\/p>\n \n 27<\/td>\n remove(Object o)<\/b><\/p>\n \n 28<\/td>\n removeAll(Collection c)<\/b><\/p>\n \n 29<\/td>\n removeAllElements()<\/b><\/p>\n \n 30<\/td>\n removeElement(Object obj)<\/b><\/p>\n \n 31<\/td>\n removeElementAt(int index)<\/b><\/p>\n \n 32<\/td>\n removeRange(int fromIndex, int toIndex)<\/b><\/p>\n \n 33<\/td>\n retainAll(Collection c)<\/b><\/p>\n \n 34<\/td>\n set(int index, Object element)<\/b><\/p>\n \n 35<\/td>\n setElementAt(Object obj, int index)<\/b><\/p>\n \n 36<\/td>\n setSize(int newSize)<\/b><\/p>\n \n 37<\/td>\n int size()<\/b><\/p>\n \n 38<\/td>\n subList(int fromIndex, int toIndex)<\/b><\/p>\n \n 39<\/td>\n Object[] toArray()<\/b><\/p>\n \n 40<\/td>\n Object[] toArray(Object[] a)<\/b><\/p>\n \n 41<\/td>\n String toString()<\/b><\/p>\n \n 42<\/td>\n void trimToSize()<\/b><\/p>\n import<\/span> java.util.ArrayList<\/span>;<\/span>\r\nimport<\/span> java.util.Vector<\/span>;<\/span>\r\n\r\npublic<\/span> class<\/span> VectorDemo2<\/span> {<\/span>\r\n\r\n\tpublic<\/span> static<\/span> void<\/span> main<\/span>(<\/span>String[]<\/span> args)<\/span> {<\/span>\r\n\r\n\t\tVector<<\/span>String><\/span> vector2 =<\/span> new<\/span> Vector<<\/span>String>();<\/span>\t\r\n\t\tvector2.<\/span>add<\/span>(<\/span>\"Kindson\"<\/span>);<\/span>\r\n\t\tvector2.<\/span>add<\/span>(<\/span>\"Saffon\"<\/span>);<\/span>\t\t\r\n\t\t\r\n\t\tfor<\/span> (<\/span>String element :<\/span>vector2)<\/span> {<\/span>\r\n\t\t\tSystem.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>element);<\/span>\r\n\t\t}<\/span>\r\n\t\t\r\n\t\tSystem.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>\"Current Size: \"<\/span> +<\/span> vector2.<\/span>size<\/span>());<\/span>\r\n\t\tSystem.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>\"Current Capacity: \"<\/span> +<\/span> vector2.<\/span>capacity<\/span>());<\/span>\r\n\t\t\r\n\t\tvector2.<\/span>ensureCapacity<\/span>(<\/span>25<\/span>);<\/span>\r\n\t\t\r\n\t\tSystem.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>\"New Size: \"<\/span> +<\/span> vector2.<\/span>size<\/span>());<\/span>\r\n\t\tSystem.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>\"New Capacity: \"<\/span> +<\/span> vector2.<\/span>capacity<\/span>());<\/span>\t\t\r\n\t\t\r\n\t\tvector2.<\/span>addElement<\/span>(<\/span>\"Oleander\"<\/span>);<\/span>\r\n\t\t\r\n\t\tSystem.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>vector2.<\/span>isEmpty<\/span>());<\/span>\r\n\t}<\/span>\r\n}<\/span>\r\n<\/pre>\n