Remove n number of dot(.) from String in Java [duplicate] - java

This question already has answers here:
Trim leading or trailing characters from a string?
(6 answers)
Closed 5 years ago.
I have the following string and I want to remove dynamic number of dot(.) at the end of the String.
"abc....."
Dot(.) can be more than one

Try this. It uses a regular expression to replace all dots at the end of your string with empty strings.
yourString.replaceAll("\\.+$", "");

Could do this to remove all .:
String a = "abc.....";
String new = a.replaceAll("[.]", "");
Remove just the trailing .'s:
String new = a.replaceAll("//.+$","");
Edit: Seeing the comment. To remove last n .'s
int dotsToRemove = 5; // whatever value n
String new = a.substring(0, s.length()-dotsToRemove);

how about using this function? seems to work faster than regex
public static String trimPoints(String txt)
{
char[] cs = txt.toCharArray();
int index =0;
for(int x =cs.length-1;x>=0;x--)
{
if(cs[x]=='.')
continue;
else
{
index = x+1;
break;
}
}
return txt.substring(0,index);
}

Related

Java 8, updating element in array [duplicate]

This question already has answers here:
How do I compare strings in Java?
(23 answers)
Closed 4 years ago.
I have trouble with my code. I need to replace element in Array if condition is true.
Inputs are:
dashedCapital = "------";
input = "a";
capital = "Warsaw";
Code should check if capital contains input and if yes replace "-" in dashedCapital to character from input at specified position:
public static String changeDashedCapital(String dashedCapital, String input, String capital){
String[] capitalArray = capital.split("");
String[] dashedCapitalArray = dashedCapital.split("");
String[] character = input.split("");
for(int i = 0; i < capitalArray.length; i++){
//System.out.println(i);
//System.out.println(capitalArray[i] + character[0] + dashedCapitalArray[i]);
if(capitalArray[i] == character[0]){
dashedCapitalArray[i] = character[0];
}
}
String result = Arrays.toString(dashedCapitalArray);
System.out.println(result);
return result;
}
Result is "------" but should be "-a--a-". What's going wrong?
John, thanks for your reply, it was helpful.
I edited my method so it's look like this now:
public static String changeDashedCapital(String dashedCapital, String input, String capital){
for(int i = 0; i < capital.length(); i++){
if(capital.charAt(i).equals(input.charAt(0))) {
String new_dashed = dashedCapital.substring(0,i)+input.charAt(0)+dashedCapital.substring(i);
System.out.println(new_dashed);
}
}
return "OK:";
Now i get this error:
GetWord.java:69: error: char cannot be dereferenced
if(capital.charAt(i).equals(input.charAt(0))) {
^
1 error
I don't understand why it's wrong. I using a equals() function. I also tried "==" operator but then nothing happens. What does it mean "char cannot be dereferenced"? How I could compare single chars from string with another chars from another string?
The reason it is not working is because your if for character equality is never true. You’re comparing strings of length 1 and not characters. You can quickly fix by changing if be using the string comparing function .equals()
if(capitalArray[i].equals(character[0])){
...
}
However, you should change your code and not just use this fix. Don’t split your stings into arrays, just use the .charAt() method to get a character at a particular index.

Split a String using split function to count number of "that" [duplicate]

This question already has answers here:
Find the Number of Occurrences of a Substring in a String
(27 answers)
Closed 5 years ago.
String str = "ABthatCDthatBHthatIOthatoo";
System.out.println(str.split("that").length-1);
From this I got 4. that is right but if last that doesn't have any letter after it then it shows wrong answer '3' as in :
String str = "ABthatCDthatBHthatIOthat";
System.out.println(str.split("that").length-1);
I want to count the occurrence of "that" word in given String.
You could specify a limit to account for the final 'empty' token
System.out.println(str.split("that", -1).length-1);
str.split("that").length doesn't count the number of 'that's . It counts the
number of words that have 'that' in between them
For example-
class test
{
public static void main(String args[])
{
String s="Hi?bye?hello?goodDay";
System.out.println(s.split("?").length);
}
}
This will return 4, which is the number of words separated by "?".
If you return length-1, in this case, it will return 3, which is the correct count of the number of question marks.
But, what if the String is : "Hi????bye????hello?goodDay??"; ?
Even in this case, str.split("?").length-1 will return 3, which is the incorrect count of the number of question marks.
The actual functionality of str.split("that //or anything") is to make a String array which has all those characters/words separated by 'that' (in this case).The split() function returns a String array
So, the above str.split("?") will actually return a String array : {"Hi,bye,hello,goodDay"}
str.split("?").length is returning nothing but the length of the array which has all the words in str separated by '?' .
str.split("that").length is returning nothing but the length of the array which has all the words in str separated by 'that' .
Here is my link for the solution of the problem link
Please tell me if you have any doubt.
Find out position of substring "that" using lastIndexOf() and if its at last position of the string then increment the cout by 1 of your answer.
Try this
String fullStr = "ABthatCDthatBHthatIOthatoo";
String that= "that";
System.out.println(StringUtils.countMatches(fullStr, that));
use StringUtils from apache common lang, this one https://commons.apache.org/proper/commons-lang/javadocs/api-2.6/src-html/org/apache/commons/lang/StringUtils.html#line.170
I hope this would help
public static void main(String[] args) throws Exception
{ int count = 0;
String str = "ABthatCDthatBHthatIOthat";
StringBuffer sc = new StringBuffer(str);
while(str.contains("that")){
int aa = str.indexOf("that");
count++;
sc = sc.delete(aa, aa+3);
str = sc.toString();
}
System.out.println("count is:"+count);
}

how to print first Characters from multiple string in java? [duplicate]

This question already has answers here:
Get string character by index
(13 answers)
Closed 8 years ago.
i want to print first character from multiple word , this word coming from api , like
DisplayName: arwa othman .
i want to print the letter (a) and (o).
can anyone to help me please ??
Try this
public String getFirstWords(String original){
String firstWord= "";
String[] split = original.split(" ");
for(String value : split){
firstWord+= value.substring(0,1);
}
return firstWord;
}
And use this as
String Result = getFirstWords("arwa othman");
Edit
Using Regex
String name = "arwa othman";
String firstWord= "";
for(String s : name.split("\\s+")){
firstWord += s.charAt(0);
}
String Result = firstWord;
You can use the the Apache Commons Langs library and use the initials() method , you can get more information from here http://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/text/WordUtils.html#initials(java.lang.String)
I am quoting a sample code snippet that might be useful :
WordUtils.initials(null) = null
WordUtils.initials("") = ""
WordUtils.initials("Ben John Lee") = "BJL"
WordUtils.initials("Ben J.Lee") = "BJ"
This may work for you:
String[] splitArray = displayName.split("\\s+");
char[] initials = new char[splitArray.length];
for (int i = 0; i < splitArray.length; i++) {
initials[i] = splitArray[i].charAt(0);
}
This will give you a char array. If you want a String array use String.valueOf(char)

How to count words in String [duplicate]

This question already has answers here:
How do I count the number of words in a string?
(8 answers)
Closed 9 years ago.
I want to count the words in my String in a int variable.
For example:
String text = "Hello my friends";
int number = 3;
or
String text = "I think it is better to go";
int number = 7;
How can I do that?
String text = "I think it is better to go";
int number = text.split(" ").length;
You can try following method.
int countWords (String input) {
String trim = in.trim();
if (trim.isEmpty()) return 0;
//separate string around spaces
return trim.split("\\s+").length;
}
Use text.split(" "); which will return you an Array of Strings. You can find the number of words by getting the size of that array.
Try to split the string with space string("\\s+") and count the size of array.

First char to upper case [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
How to upper case every first letter of word in a string?
Most efficient way to make the first character of a String lower case?
I want to convert the first letter of a string to upper case. I am attempting to use replaceFirst() as described in JavaDocs, but I have no idea what is meant by regular expression.
Here is the code I have tried so far:
public static String cap1stChar(String userIdea)
{
String betterIdea, userIdeaUC;
char char1;
userIdeaUC = userIdea.toUpperCase();
char1 = userIdeaUC.charAt(0);
betterIdea = userIdea.replaceFirst(char1);
return betterIdea;
}//end cap1stChar
The compiler error is that the argument lists differ in lengths. I presume that is because the regex is missing, however I don't know what that is exactly.
Regular Expressions (abbreviated "regex" or "reg-ex") is a string that defines a search pattern.
What replaceFirst() does is it uses the regular expression provided in the parameters and replaces the first result from the search with whatever you pass in as the other parameter.
What you want to do is convert the string to an array using the String class' charAt() method, and then use Character.toUpperCase() to change the character to upper case (obviously). Your code would look like this:
char first = Character.toUpperCase(userIdea.charAt(0));
betterIdea = first + userIdea.substring(1);
Or, if you feel comfortable with more complex, one-lined java code:
betterIdea = Character.toUpperCase(userIdea.charAt(0)) + userIdea.substring(1);
Both of these do the same thing, which is converting the first character of userIdea to an upper case character.
Or you can do
s = Character.toUpperCase(s.charAt(0)) + s.substring(1);
public static String cap1stChar(String userIdea)
{
char[] stringArray = userIdea.toCharArray();
stringArray[0] = Character.toUpperCase(stringArray[0]);
return userIdea = new String(stringArray);
}
Comilation error is due arguments are not properly provided, replaceFirst accepts regx as initial arg. [a-z]{1} will match string of simple alpha characters of length 1.
Try this.
betterIdea = userIdea.replaceFirst("[a-z]{1}", userIdea.substring(0,1).toUpperCase())
String toCamelCase(String string) {
StringBuffer sb = new StringBuffer(string);
sb.replace(0, 1, string.substring(0, 1).toUpperCase());
return sb.toString();
}
userIdeaUC = userIdea.substring(0, 1).toUpperCase() + userIdea.length() > 1 ? userIdea.substring(1) : "";
or
userIdeaUC = userIdea.substring(0, 1).toUpperCase();
if(userIdea.length() > 1)
userIdeaUC += userIdea.substring(1);
For completeness, if you wanted to use replaceFirst, try this:
public static String cap1stChar(String userIdea)
{
String betterIdea = userIdea;
if (userIdea.length() > 0)
{
String first = userIdea.substring(0,1);
betterIdea = userIdea.replaceFirst(first, first.toUpperCase());
}
return betterIdea;
}//end cap1stChar

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