【Java开源代码栏目提醒】:本文主要为网学会员提供ArrayListOtherDemo.java,希望对需要ArrayListOtherDemo.java网友有所帮助,学习一下!
package chapter9;
import java.util.ArrayList;
import java.util.Iterator;
public class ArrayListOtherDemo {
public static void main(String[] args) {
ArrayList<String> col = new ArrayList<String>();
for (int i = 0; i < 5; i++) {
col.add(String.valueOf(i));
}
System.out.println("开始时 col中的元素有:");
for (int i = 0; i < col.size(); i++)
System.out.println("element at " + i + " is " + col.get(i));
// 判断是否包含一个元素
String s = new String("4");
System.out.println("the element 4 is in col is " + col.contains(s));
// 确保col的大小
System.out.println("col.size before = " + col.size());
ArrayList<String> arrl = new ArrayList<String>(10);
for (int i = 0; i < 3; i++) {
arrl.add(0, "one");
arrl.add(1, "two");
}
col.ensureCapacity(11);
col.addAll(arrl);
System.out.println("col.size after = " + col.size());
// 输出新的col的所有元素
String element;
for (Iterator<String> iter = col.iterator(); iter.hasNext();) {
element = iter.next();
System.out.println("element is " + element);
}
// 将其赋值给一个数组
// String[] arr=(String [])col.toArray();
String[] arr = new String[col.size()];
arr = (String[]) col.toArray(arr);
for (int i = 0; i < arr.length; i++) {
System.out.println("the element at " + i + " is " + arr[i]);
}
// 判断col是否为空
System.out.println("before col is empty is " + col.isEmpty());
col.clear();
System.out.println("after col is empty is " + col.isEmpty());
}
}