/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a = 1 ; int b = 3; int c = 5; ArrayList list = new ArrayList(); list.add(a); list.add(b); list.add(c); int randomValue = 0; Random random = new Random(); for(int i=0;i<=20;i++){ randomValue = random.nextInt(3); // System.out.println(randomValue); System.out.println(list.get(randomValue)); } }
public static void main(String args[]) { List list=new ArrayList(); list.add("1"); list.add("2"); list.add("3"); list.add("4"); for(int i=list.size();i>0;i--) { int a=new Random().nextInt(i==0?1:i); System.out.println(list.get(a)); list.remove(a); } }
你先吧数放入一个list,你可以用collection 的shuffle方法
public static void main(String[] args) { List<Integer> list = new ArrayList<Integer>(); for (int i = 0; i < 3; i++) { list.add(i); } System.out.println(list.toString()); Collections.shuffle(list); System.out.println(list.toString()); }
public static void main(String[] args) {
String[] arr = {"a" , "b" , "c"} ;
for(int i = arr.length ; i >= 1 ; i--){
int rand = (int)(Math.random() * i) ;
System.out.println(arr[rand]) ;
if(rand != arr.length - 1){
String str ;
str = arr[rand] ;
arr[rand] = arr[i -1] ;
arr[i -1] = str ;
}
}
}
}
看看这个行吗
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int a = 1 ;
int b = 3;
int c = 5;
ArrayList list = new ArrayList();
list.add(a);
list.add(b);
list.add(c);
int randomValue = 0;
Random random = new Random();
for(int i=0;i<=20;i++){
randomValue = random.nextInt(3);
// System.out.println(randomValue);
System.out.println(list.get(randomValue));
}
}
for(int i=0;i<list.size();i++)
{
System.out.println(list.get(new Random().nextInt(i+1)));
list.remove(new Random().nextInt(i+1));}
public static void main(String args[])
{
List list=new ArrayList();
list.add("1");
list.add("2");
list.add("3");
list.add("4");
for(int i=list.size();i>0;i--)
{
int a=new Random().nextInt(i==0?1:i);
System.out.println(list.get(a));
list.remove(a);
}
}
List<Integer> list = new ArrayList<Integer>();
for (int i = 0; i < 3; i++) {
list.add(i);
}
System.out.println(list.toString());
Collections.shuffle(list);
System.out.println(list.toString());
}