1.list方法：
public class Demo4 {
public static String notRepest2(String str){
ArrayList list = new ArrayList();
String newsString="";
for (int i = 0; i < str.length(); i++) {
if (list.contains(str.charAt(i))==false) {
list.add(str.charAt(i));
}
}
for (Object obj : list) {
newsString+=obj;
}
return newsString;
}
public static void main(String[] args) {
System.out.println(Demo4.notRepest2("hyyydyhrjytutjujt"));
}
}
输出结果：
2.set方法：
public class Demo2 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("输入字符串：");
String a = sc.next();
char[] b = a.toCharArray();
HashSet set = new HashSet();
StringBuilder aaa = new StringBuilder();
for (int i = 0; i < b.length; i++) {
if(set.add(b[i])){
aaa.append(b[i]);
}
}
System.out.println(aaa);
}
}
输出结果：
3.HashMap方法：
public class Demo5 {
public static String notrepeat5(String str){
String result = "";
Map map = new HashMap();
for (int i = 0; i < str.length(); i++) {
String a = str.charAt(i)+"";
map.put(a, i);
}
Iterator iterator = map.keySet().iterator();
while(iterator.hasNext()){
result = result + iterator.next();
}
return result;
}
public static void main(String[] args) {
Demo5 a = new Demo5();
String b = a.notrepeat5("asdqwad");
System.out.println(b);
}
}
输出结果：
