{
String arr[] = {"a", "b", "a", "a", "b",
"c", "c", "d"}
//直接使用Set的不允许内容重复的特性,自动去掉重复的
Set<String>filterSet = new HashSet<String>()
for (String str : arr)
{
filterSet.add(str)
}
System.out.println(filterSet)
}
import java.util.HashSetimport java.util.Scanner
public class Test {
public static void main(String[] args) {
System.out.println("请输入一句英文:")
Scanner sca = new Scanner(System.in)
String s=sca.next()
char[] c1 = s.toCharArray()
HashSet<Character>hs=new HashSet<Character>()
for (int i = 0i <c1.lengthi++) {
hs.add(c1[i])
}
System.out.println("这句英文中共出现了"+hs.size()+"个字母")
System.out.println("所有的字母是:")
for(int i=0i<hs.size()i++){
System.out.print(hs.toArray()[i])
}
}
}
ArrayList a = new ArrayList(数组)for(int i = 0 i<a.size()i++){
Object obj = a[i]
if(a.contains(obj)){
a.remove(i)
}
}