请问有谁能告诉我如何从中删除重复的值?
String s="Bangalore-Chennai-NewYork-Bangalore-Chennai";
输出应该如下所示
String s="Bangalore-Chennai-NewYork-";
使用Java..
任何帮助将不胜感激。
请问有谁能告诉我如何从中删除重复的值?
String s="Bangalore-Chennai-NewYork-Bangalore-Chennai";
输出应该如下所示
String s="Bangalore-Chennai-NewYork-";
使用Java..
任何帮助将不胜感激。
这可以一行代码搞定:
public String deDup(String s) {
return new LinkedHashSet<String>(Arrays.asList(s.split("-"))).toString().replaceAll("(^\\[|\\]$)", "").replace(", ", "-");
}
public static void main(String[] args) {
System.out.println(deDup("Bangalore-Chennai-NewYork-Bangalore-Chennai"));
}
输出:
Bangalore-Chennai-NewYork
注意顺序得以保留 :)
关键点如下:
split("-")
将不同的值作为数组返回Arrays.asList()
将该数组转换为ListLinkedHashSet
保留插入顺序以及唯一性-它完成了提供唯一值的所有工作,这些唯一值通过构造函数传递toString()
方法返回的格式为:[元素1, 元素2, ...]
replace
命令从toString()
结果中删除了“标点符号”此解决方案要求值不包含字符序列", "
-对于如此简洁的代码而言,这是一个合理的要求。
当然,这只有一行代码:
public String deDup(String s) {
return Arrays.stream(s.split("-")).distinct().collect(Collectors.joining("-"));
}
如果您不关心保留顺序(即删除重复项的第一个出现是可行的):
public String deDup(String s) {
return s.replaceAll("(\\b\\w+\\b)-(?=.*\\b\\1\\b)", "");
}
public static String removeDuplicates(String txt, String splitterRegex)
{
List<String> values = new ArrayList<String>();
String[] splitted = txt.split(splitterRegex);
StringBuilder sb = new StringBuilder();
for (int i = 0; i < splitted.length; ++i)
{
if (!values.contains(splitted[i]))
{
values.add(splitted[i]);
sb.append('-');
sb.append(splitted[i]);
}
}
return sb.substring(1);
}
使用方法:
String s = "Bangalore-Chennai-NewYork-Bangalore-Chennai";
s = removeDuplicates(s, "\\-");
System.out.println(s);
输出:
Bangalore-Chennai-NewYork
你可以将字符串添加到 HashSet 中。
代码片段:
Set<String> set = new HashSet<String>();
for(int i=0; i < arr.length; i++){
if(set.contains(arr[i])){
System.out.println("Duplicate string found at index " + i);
} else {
set.add(arr[i]);
}
static String RemoveDuplicateCharInString(String s){
for (int i = 0; i < s.length(); i++) {
if((s.substring(i+1)).indexOf(s.charAt(i))!=-1){
s=s.substring(0,i+1)+(s.substring(i+1)).replaceAll(""+s.charAt(i),"");
}
}
return s;
}
通过使用-
进行分割创建字符串数组,然后从中创建一个哈希集。
String s="Bangalore-Chennai-NewYork-Bangalore-Chennai";
String[] strArr = s.split("-");
Set<String> set = new HashSet<String>(Arrays.asList(strArr));
String[] result = new String[set.size()];
set.toArray(result);
String s="Bangalore-Chennai-NewYork-Bangalore-Chennai";
String[] strArr = s.split("-");
Set<String> set = new LinkedHashSet<String>(Arrays.asList(strArr));
String[] result = new String[set.size()];
set.toArray(result);
StringBuilder res = new StringBuilder();
for (int i = 0; i < result.length; i++) {
String string = result[i];
if(i==result.length-1)
res.append(string);
else
res.append(string).append("-");
}
System.out.println(res.toString());
输出:-
Bangalore-Chennai-NewYork
实现思路:
Collection
中Collection
并删除重复项Collection
构建新字符串最棘手的部分应该是第3步,但并非不可能。如果使用Set
,则可以跳过此步骤。
编辑:也许您可以在添加元素之前进行存在性检查以替代第2&3步。
String reason = "Word1 , Word2 , Word3";
HashMap<String,String> temp_hash = new HashMap<String,String>();
StringBuilder reason_fixed = new StringBuilder();
//in:
for(String word : reason.split(",")){
temp_hash.put(word,word);
}
//out:
for(String words_fixed : temp_hash.keySet()){
reason_fixed.append(words_fixed + " , ");
}
//print:
System.out.println(reason_fixed.toString());
public static void main(String[] args) {
String str="Bangalore-Chennai-Newyork-Bangalore-Chennai";
String output="";
String [] arr=str.split("-");
LinkedHashSet<String> lhs=new LinkedHashSet<String>();
for (int i = 0; i < arr.length; i++) {
lhs.add(arr[i]);
}
for(String s:lhs){
output=output+s+"-";
}
System.out.println(output);
}
public class RemDuplicateWordFromString {
public static void main(String[] args) {
String s1 = "Hello India Hello India Hello India Hello India";
countWords(s1);
}
public static void countWords(String s1) {
String[] s2 = s1.split(" ");
for (int i = 0; i < s2.length; i++) {
for (int j = i + 1; j < s2.length; j++) {
if (s2[i].equals(s2[j])) {
if (i != j) {
s2[i] = "";
}
}
}
}
for (int i = 0; i < s2.length; i++) {
if (s2[i] != "") {
System.out.print(s2[i] + " ");
}
}
}
}
StringBuilder builderWord = new StringBuilder(word);
for(int index=0; index < builderWord.length(); index++) {
for(int reverseIndex=builderWord.length()-1; reverseIndex > index;reverseIndex--) {
if (builderWord.charAt(reverseIndex) == builderWord.charAt(index)) {
builderWord.deleteCharAt(reverseIndex);
}
}
}
return builderWord.toString();
"-"
吗? - Martijn Courteaux