List Collection Class

1.1:list.add Method--Add an object to the list of collections

public static void Main (string[] args) {

List<string> list=new arraylist<string> ();
List.add ("Environmental protection"); Add data to the list
List.add ("Love the Earth"); Add data to the list
List.add ("Starting from Me"); Add data to the list
By looping through the contents of the list
for (int i=0;i<list.size (); i++) {
System.out.println (i+ ":" +list.get (i));
}
}

1.1.1:

void Add (int index, E Element)

Index: Used to specify the indexes in which to insert the specified element.

element: Used to specify which elements to insert.

The index value starts at 0.

public static void Main (string[] args) {
List<string> list=new arraylist<string> ();
List.add ("Environmental protection"); Add data to the list
List.add ("Love the Earth"); Add data to the list
List.add ("Starting from Me"); Add data to the list
List.add (1, "Starting from Me"); Add data at the location of the 1th + 1 element
By looping through the contents of the list
for (int i=0;i<list.size (); i++) {
System.out.println (i+ ":" +list.get (i));
}
}

1.2:list.addall Method--Add all elements to the list

public static void Main (string[] args) {
List<string> list=new arraylist<string> ();
List.add ("Environmental protection"); Add data to the list
List.add ("Love the Earth"); Add data to the list
List.add ("Starting from Me"); Add data to the list
List.add (1, "Starting from Me"); Add data at the location of the 1th + 1 element
List<string> list_ad=new arraylist<string> ();
List_ad.add ("Public service advertisement");
Add all the elements in the list to the List_ad
System.out.println ("Add Succeeded:" +list_ad.addall (list));
By looping through the contents of the list
for (int i=0;i<list_ad.size (); i++) {
System.out.println (i+ ":" +list_ad.get (i));
}
}

1.2.1:

public static void Main (string[] args) {

List<string> list=new arraylist<string> ();
List.add ("Environmental protection"); Add data to the list
List.add ("Love the Earth"); Add data to the list
List.add ("Starting from Me"); Add data to the list
List<string> list_ad=new arraylist<string> ();
List_ad.add ("Public service advertisement");
List_ad.add ("Thank you for watching");
Add all the elements in the list to the List_ad
System.out.println ("Add Succeeded:" +list_ad.addall (1,list));
By looping through the contents of the list
for (int i=0;i<list_ad.size (); i++) {
System.out.println (i+ ":" +list_ad.get (i));
}

}

1.3 List.clear Method--Remove all elements from the list

public static void Main (string[] args) {
list<string> list = new arraylist<string> ();
List.add ("Environmental protection"); Add data to the list
List.add ("Love the Earth"); Add data to the list
List.add ("Starting from Me"); Add data to the list
SYSTEM.OUT.PRINTLN ("Data in the list collection before using the Clear method");
for (int i = 0; i < list.size (); i++) {//by looping through the contents of the list
SYSTEM.OUT.PRINTLN (i + ":" + list.get (i));
}
System.out.println ("After using the clear method, the data in the list collection");
List.clear (); Remove all elements
if (list.size () <= 0) {
System.out.println ("The list object is empty! ");
}
}

1.4 List.contains Method--Determines whether the list contains the specified element

public static void Main (string[] args) {
list<string> list = new arraylist<string> ();
List.add ("Strawberry"); Add data to the list
List.add ("banana"); Add data to the list
List.add ("pineapple"); Add data to the list
for (int i = 0; i < list.size (); i++) {//by looping through the contents of the list
SYSTEM.OUT.PRINTLN (i + ":" + list.get (i));
}
String o = "Apple";
System.out.println ("The list object contains elements" + O + ":" + list.contains (o));
Determines whether the string contains the specified string object
}

1.5 List.get Method--Gets the element at the specified position in the list

public static void Main (string[] args) {
List<string> list=new arraylist<string> ();
List.add ("Environmental protection"); Add data to the list
List.add ("Love the Earth"); Add data to the list
List.add ("Starting from Me"); Add data to the list
String Ret=list.get (1);
System.out.println ("Gets the element with index position 1:" +ret);
}

1.6 List.isEmpty Method--Judging whether the collection object is empty

public static void Main (string[] args) {
List<string> list=new arraylist<string> ();
List.add ("Environmental protection"); Add data to the list
List.add ("Starting from Me"); Add data to the list
List.add ("Love the Earth"); Add data to the list
List.add ("Starting from Me"); Add data to the list
Boolean empty=list.isempty ();
if (empty) {
System.out.println ("The list is empty");
}else{
System.out.println ("The list is not empty");
}
List.clear (); Remove all elements from the list
SYSTEM.OUT.PRINTLN ("After executing the Clear method");
Empty=list.isempty ();
if (empty) {
System.out.println ("The list is empty");
}else{
System.out.println ("The list is not empty");
}
}

1.7 List.iterator Method--Iterate over list elements

public static void Main (string[] args) {
List<string> list=new arraylist<string> (); Defining a List Collection object
List.add ("Environmental protection"); Add data to the list
List.add ("Love the Earth"); Add data to the list
List.add ("Starting from Me"); Add data to the list
Iterator It=list.iterator (); Get Iterator Object
while (It.hasnext ()) {//loops through iterator objects
System.out.println (It.next ()); Output the value in the Iterator object
}
}

1.8 List.remove Method--Removes the specified element from the list

public static void Main (string[] args) {
List<string> list=new arraylist<string> ();
List.add ("Apple"); Add data to the list
List.add ("Strawberry"); Add data to the list
List.add ("banana"); Add data to the list
String Str=list.remove (1); Remove an element with an index position of 1
System.out.println ("I do not like to eat fruit is:" +str);
Iterator It=list.iterator (); Gets the iterator object for the collection
System.out.println ("The fruit that loves to eat is:");
while (It.hasnext ()) {//Traverse iterator Object
System.out.println (It.next ()); Output iterator elements in an object
}
}

1.9 List.removeall Method--Remove all elements from the list

public static void Main (string[] args) {
  List<String> List = new arraylist<string> ();
  list.add ("Protect the Environment");      //Add data to the list
  list.add ("Love the Earth");       //Add data to the list
  list.add ("Start from Me");       //Add data to the list
  List<String> list1 = new arraylist<string> ();
  list1.add ("Environmental protection");       //Add data to the list
  list1.add ("Love the Earth");       //Add data to the list
  boolean ret = List.removeall (list1);   //Remove the same element as List1 from the list
  Iterator<String> it = list.iterator ();  //Create iterator
  while (It.hasnext ()) {       //loop-through iterator
   system.out.println (It.next ());    //Output set element
  }
}

Run the program, remove the contents of the List1 from the collection list, and iterate through the collection list, resulting in "starting from Me".

2.0 List.size Method--Returns the number of elements in a list

public static void Main (string[] args) {
List<string> list=new arraylist<string> ();
List.add ("Environmental protection"); Add data to the list
List.add ("Love the Earth"); Add data to the list
List.add ("Starting from Me"); Add data to the list
int listsize=list.size (); Get the number of elements in a list
System.out.println ("Number of elements in the list:" +listsize);
}

Run the program, and the number of elements in the output list is 3.

2.1 List.sublist Method--Gets the child list of the specified range in the list

sublist (int fromIndex, int toindex)

FromIndex: Used to specify the starting point (including the point) of the new list.

Toindex: Used to specify the end point of the new list (excluding that point).

public static void Main (string[] args) {
list<string> list = new arraylist<string> ();
List.add ("Javaweb Programming Dictionary"); Add data to the list
List.add ("Java Programming dictionary"); Add data to the list
List.add ("C # Programming Dictionary"); Add data to the list
List.add ("ASP.        NET programming dictionary "); Add data to the list
List.add ("VC Programming Dictionary"); Add data to the list
List.add ("SQL Programming Dictionary"); Add data to the list
iterator<string> its = List.iterator (); Get Collection iterator
SYSTEM.OUT.PRINTLN ("All element objects in the collection:");
while (Its.hasnext ()) {//loops through the collection
System.out.print (Its.next () + ""); Output Collection Contents
}
list<string> sublist = List.sublist (3, 5); Get child list
System.out.println ("\ n intercept some elements of the collection:");
Iterator it = Sublist.iterator ();
while (It.hasnext ()) {
System.out.print (It.next () + "");
}
}

List Collection Class