Java中的集合类,集合类有哪些,如何增添删除元素,如何遍历
http://www.cnblogs.com/LittleHann/p/3690187.html
import java.util.*; public class TestCollection { public static void main(String[] args) { Collection arrayList = new ArrayList(); arrayList.add("====天晴朗====="); arrayList.add("====暖花儿朵朵绽放====="); arrayList.add("====暖花儿朵朵绽放====="); arrayList.add("====暖花儿朵朵绽放====="); arrayList.add("====暖花儿朵朵绽放====="); arrayList.add("====暖花儿朵朵绽放====="); System.out.println(arrayList); System.out.println(arrayList.size()); Object[] objs = arrayList.toArray(); for(int i = 0 ; i < objs.length ; i++){ System.out.println(objs[i]); } Collection linkedList = new LinkedList(); linkedList.add("====天晴朗====="); linkedList.add("====暖花儿朵朵绽放====="); linkedList.add("====暖花儿朵朵绽放====="); linkedList.add("====暖花儿朵朵绽放====="); linkedList.add("====暖花儿朵朵绽放====="); linkedList.add("====暖花儿朵朵绽放====="); System.out.println(linkedList); System.out.println(linkedList.size()); Object[] linkedobjs = linkedList.toArray(); for(int i = 0 ; i < linkedobjs.length ; i++){ System.out.println(linkedobjs[i]); } Collection vector = new Vector(); vector.add("====天晴朗====="); vector.add("====暖花儿朵朵绽放====="); vector.add("====暖花儿朵朵绽放====="); vector.add("====暖花儿朵朵绽放====="); vector.add("====暖花儿朵朵绽放====="); vector.add("====暖花儿朵朵绽放====="); System.out.println(vector); System.out.println(vector.size()); Object[] vectors = vector.toArray(); for(int i = 0 ; i < vectors.length ; i++){ System.out.println(vectors[i]); } Collection hashSet = new HashSet(); hashSet.add("====天晴朗====="); hashSet.add("====暖花儿朵朵绽放====="); hashSet.add("====暖花儿朵朵绽放====="); hashSet.add("====暖花儿朵朵绽放====="); hashSet.add("====33333====="); hashSet.add("========="); System.out.println(hashSet); System.out.println(hashSet.size()); hashSet.remove("========="); System.out.println(hashSet); System.out.println(hashSet.size()); //SortedSet是抽象的,不能被实例化 //'SortedSet' is abstract; cannot be instantiated //Collection sortedset = new SortedSet(); //EnumSet是抽象的,不能被实例化 //'EnumSet' is abstract; cannot be instantiated //Collection enumset =new EnumSet(); } }
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