如何将数组存储在单个数组中？例如,我有四个不同的数组,我想将它存储在单个数组中int storeAllArray [],当我调用例如storeAllArray [1]时,我会得到这个输出[11,65,4,3,2,9,7]而不是单个元素？
int array1 [] = {1,2,3,4,5,100,200,400};
int array2 [] = {2,6,5,7,2,5,10};
int array3 [] = {11,65,4,3,2,9,7};
int array4 [] = {111,33,22,55,77};
int storeAllArray [] = {array1,array2,array3,array2} //我希望将所有数组存储在数组中
for (int i=0; i<storeAllArray; i++){
System.out.println(storeAllArray.get[0]); // e.g. will produce --> 1,2,3,4,5,100,200,400 , how can I do this?
}
编辑:我怎样才能获得这样的输出？
System.out.println(storeAllArray [0]) --> [1,2,3,4,5,100,200,400];
System.out.println(storeAllArray [1]) --> [2,6,5,7,2,5,10];
System.out.println(storeAllArray [2]) --> [11,65,4,3,2,9,7];
System.out.println(storeAllArray [2]) --> [111,33,22,55,77];
int A = 300;
int B = 400;
int C = 1000;
int D = 500;
int []abcd = {A,B,C,D};
Arrays.sort(abcd); // the sequence of array elements will be {300, 400, 500,1000}
我想根据它们在排序后在数组中的位置来改变变量A,B,C,D的值.
例如,变量A位于索引0处,因此A的值变为1而不是300,变量B位于索引1处,因此B的值变为2而不是400,变量D位于索引2处,因此D的值变为3而不是500,变量C位于索引3,因此C的值变为4而不是1000,
变量的最终值为:A = 1; B = 2; C = 4; D = 3;
我创建了计时器.如何将计时器格式更改为秒,以便它不会是长号？谢谢
private long startTime = System.currentTimeMillis();
Timer timer = new Timer(1000, this);
timer.start();
timer.stop();
long endTime = System.currentTimeMillis();
long timeInMilliseconds = (endTime - startTime);
我试图在单击按钮后根据当前时间重置计时器，但是它不起作用。救命 ：-（
private long startTime = System.currentTimeMillis();
Timer timer = new Timer(1000, this);
timer.start();
timer.stop();
long endTime = System.currentTimeMillis();
long timeInMilliseconds = (endTime - startTime);
timer.reset();
我的actionListener有问题.在我点击按钮之前,似乎actionListener会自动运行？在单击按钮之前,控制台中出现"这不应出现在控制台中的控制台之前"....这很奇怪.
....
button1.addActionListener(this);
button2.addActionListener(this);
....
public void actionPerformed(ActionEvent e) {
System.out.println("This should not appear in the console before button click");
if (e.getSource()==button1)
System.out.println ("answer1");
else if (e.getSource()==button2)
System.out.println ("answer2");
.....
}
no time scores
1 10 123
2 11 22
3 12 22
4 50 55
5 60 22
6 70 66
. . .
. . .
n n n
在我的txt文件的内容之上(数千行).
1st column - number of samples
2nd column - time (from beginning to end ->accumulated)
3rd column - scores
我想创建一个新文件,该文件将是每三个分数样本的总和除以同一样本的时差.
e.g. (123+22+22)/ (12-10) = 167/2 = 83.5
(55+22+66)/(70-50) = 143/20 = 7.15
新的txt文件
83.5
7.15
.
.
.
n
到目前为止我有这个代码:
fid=fopen('data.txt')
data = textscan(fid,'%*d %d %d')
time = (data{1}) …如何比较数组中的值？
我有数组命名列表,其中包含12个元素.我看到索引0中的值是否等于索引2中的值.
我试过这个代码,但似乎没有用.
if ((list.get(0)==list.get(2) && list.get(1)==list.get(3))
{
System.out.println("equal")
}
如何在链接列表中获取数据引用/索引？
例如,如果我有这个链表
java.util.List<Polygon> triangles = new LinkedList<Polygon>();
polygon triangle, selectedTriangle;
Point startDrag,endDrag,midPoint;
....
triangles.add( new Polygon(xs, ys,3));
例如,如何将Polygon selectedTriangle设置为与链接数组列表中现有三角形之一相同？
编辑:
java.util.List<Polygon> triangles = new LinkedList<Polygon>();
polygon triangle, selectedtriangle;
....
triangles.add( new Polygon(xs, ys,3));
.....
public void mousePressed(MouseEvent e) {
....
startDrag = new Point(e.getX(), e.getY());
endDrag = startDrag;
for (Polygon p : triangles) {
if (p.contains(startDrag)) {//inside triangle
//I dont know how to set the selectedTriangle as the same with existing triangle
selectedTriangle = triangles.indexOf(p.contains(startDrag));
break; //
}
}
..... …我如何随机化对的顺序？例如,我有3个元素存储在列表中,例如A,B,C - >,它们产生AB,AC,BC对.
如何以随机顺序显示对？例如AB,AC,BC 或 BC,AB,AC 或 AC,AB,BC
ArrayList<String> s = new ArrayList<String>();
s.add("A");
s.add("B");
s.add("C");
ListGenerator lg = new ListGenerator(s);
其他类
public class ListGenerator {
private ArrayList<String> pairsX= new ArrayList<String>();
public ListGenerator(ArrayList<String> list) {
int size = list.size();
int count_pairs = 0;
// create a list of all possible combinations
for(int i = 0 ; i < size ; i++)
{
String s1 = ""+i;
for(int j = (i+1) ; j < size ; j++)
{
count_pairs++;
String s2 …我试图找出2个arrayLists的元素是否匹配.但是这段代码给了我错误,Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException因为有些元素是null.
我怎样才能解决这个问题？
String level []={"High","High","High","High","High","High"};
ArrayList<Object> n = new ArrayList<Object>(Arrays.asList(level));
String choice []={null,"High","Low","High",null,"Medium"};
ArrayList<Object> m = new ArrayList<Object>(Arrays.asList(choice));
//Check if the two arrayList are identical
for(int i=0; i<m.size(); i++){
if(!(m.get(i).equals(n.get(i)))){
result= true;
break;
}
}
return result;
}