public static void count()
{
int[] a = {2,4,1,6,0,8,2,6,0,3,8,6,7,4,2,1};
Map
for (int i = 0; i < a.length; i++)
{
if (countMap.get(a[i]) == null)
{
countMap.put(a[i], 1);
}
else
{
countMap.put(a[i], countMap.get(a[i]) + 1);
}
}
System.out.println(countMap.toString());
}
如果是每个数的个数
你是想说统计各个数值出现次数吧
public static void main(String[] args) {
HashMap map = new HashMap();
int[] numbs = {2, 4, 1, 6, 0, 8, 2, 6, 0, 4, 8, 6, 4, 7, 2, 1};
for (int i = 0; i < numbs.length; i++) {
if (map.containsKey(numbs[i])) {
map.put(numbs[i], (int) map.get(numbs[i]) + 1);
} else {
map.put(numbs[i], 1);
}
}
Set set = map.keySet();
Object[] objects = set.toArray();
for (int i = 0; i < objects.length; i++) {
System.out.println(objects[i] + "出现" + map.get(objects[i])+"次");
}
}
使用Map
计出每个数 什么意思?
每个数的个数吗?