判断数组中是否有重复的值
Integer[] ia = new Integer[] { 1, 2, 3, 1 };
Set<Integer> set = new HashSet<Integer>();
for (Integer i : ia) {
if (!set.add(i)) {
System.out.println(i + "重复");
break;
}
}
数组中的值去重复
Integer[] ia = new Integer[] { 1, 2, 3, 1 };
Set<Integer> set = new LinkedHashSet<Integer>();
for (Integer i : ia) {
set.add(i);
}
System.out.println(set);
ia = set.toArray(new Integer[0]);
}
集合包含
Set<Integer> set = new HashSet<Integer>();
set.add(1);
set.add(2);
Set<Integer> otherSet = new HashSet<Integer>();
otherSet.add(2);
otherSet.add(1);
System.out.println(set.containsAll(otherSet)); //true
otherSet.add(3);
System.out.println(set.containsAll(otherSet)); //false
A = {1,2}
B = {1,2,3}
A ⊆ B
A < B
Set
java.util.Set
A collection that contains no duplicate elements.