1.ArrayList method summary
Summary of construction methods
ArrayList()
Construct an empty list with an initial capacity of 10.
ArrayList(Collection<? extends E> c)
Constructs a list of elements that contain the specified collection, which are arranged in the order in which the collection's iterator returns them.
ArrayList(int initialCapacity)
Constructs an empty list with the specified initial capacity.
Method Summary
boolean add(E e)
Adds the specified element to the end of this list.
void add(int index, E element)
Inserts the specified element into the specified position in this list.
boolean addAll(Collection<? extends E> c)
Add all elements in the collection to the end of this list in the order of elements returned by the iterator of the specified collection.
boolean addAll(int index, Collection<? extends E> c)
Starting from the specified location, insert all elements from the specified collection into this list.
void clear()
Removes all elements from this list.
Object clone()
Returns a shallow copy of this ArrayList instance.
boolean contains(Object o)
Returns true if the specified element is included in this list.
void ensureCapacity(int minCapacity)
If necessary, increase the capacity of this ArrayList instance to ensure that it can accommodate at least the number of elements specified by the minimum capacity parameter.
E get(int index)
Returns the element at the specified position in this list.
int indexOf(Object o)
Returns the index of the specified element that first appears in this list, or -1 if this list does not contain elements.
boolean isEmpty()
Return true if there are no elements in this list
int lastIndexOf(Object o)
Returns the index of the last time the specified element appears in this list, or -1 if this list does not contain an index.
E remove(int index)
Removes elements at the specified position in this list.
boolean remove(Object o)
Removes the specified element that appears for the first time in this list (if present).
protected void removeRange(int fromIndex, int toIndex)
Removes all elements in the list that are indexed between fromIndex (including) and toIndex (excluding).
E set(int index, E element)
Replaces the element at the specified position in this list with the specified element.
int size()
Returns the number of elements in this list.
Object[] toArray()
Returns an array containing all elements in this list in the appropriate order (from the first to the last element).
<T> T[] toArray(T[] a)
Returns an array containing all elements in this list in the appropriate order (from the first to the last element); the runtime type of the return array is the runtime type of the specified array.
void trimToSize()
Resizes the capacity of this ArrayList instance to the current size of the list.
2.js implements some functions
The code copy is as follows:
<html>
<script type="text/javascript" src="json.js"></script>
<head>
<script type="text/javascript">
function ArrayList(){
this.arr=[],
this.size=function(){
return this.arr.length;
},
this.add=function(){
if(arguments.length==1){
this.arr.push(arguments[0]);
}else if(arguments.length>=2){
var deleteItem=this.arr[arguments[0]];
this.arr.splice(arguments[0],1,arguments[1],deleteItem)
}
return this;
},
this.get=function(index){
return this.arr[index];
},
this.removeIndex=function(index){
this.arr.splice(index,1);
},
this.removeObj=function(obj){
this.removeIndex(this.indexOf(obj));
},
this.indexOf=function(obj){
for(var i=0;i<this.arr.length;i++){
if (this.arr[i]===obj) {
return i;
};
}
return -1;
},
this.isEmpty=function(){
return this.arr.length==0;
},
this.clear=function(){
this.arr=[];
},
this.contains=function(obj){
return this.indexOf(obj)!=-1;
}
};
// Create a new List
var list=new ArrayList();
//Add an element
list.add("0").add("1").add("2").add("3");
//Add a designated location
list.add(2,"22222222222222");
//Delete the specified element
list.removeObj("3");
//Delete the specified location element
list.removeIndex(0);
for(var i=0;i<list.size();i++){
document.writeln(list.get(i));
}
document.writeln(list.contains("2"))
</script>
</head>
<body>
</body>
</html>