Develop Reference

how to start count upto 1 until press comma(,) it should count tow

its may be silly but am confused on that this i want to start count up to one and if press comma(,)then i want to count comma only, here how i am try.
String conCount;
conCount = "1";
int countComma = conCount.length() - conCount.replace(",", "").length();
String lenVar;
lenVar = conCount;
convert = String.valueOf(countComma);
if (conCount.length() == 0) {
lenVar = "0";
} else {
textViewConCount.setText(convert);
}

String editTextString = "abc,efg,pqr,xyz";
if (editTextString.contains(",")) {
int countStringsSeperatedByComma = 0;
countStringsSeperatedByComma = editTextString.split(",").length;
System.out.println("Count of strings seperated by comma : " + countStringsSeperatedByComma);
int commaCount = countStringsSeperatedByComma - 1;
System.out.println("Count of commas : " + commaCount);
} else {
System.out.println("Count of characters in editText string : " + editTextString.length());
}
Output for above condition will be :
Count of strings seperated by comma : 4
Count of commas : 3
Suppose if your string is "abcefgpqrxyz" i.e. without comma then it will execute else part and print characters count as 12 in this case
Count of characters in editText string : 12

Your question statement is so ambiguous. Elaborate it completely and explain your end result with example. It's regarding string functions, I can give you the answer about it if I understand it :) :D

thanks for that i got that answer like that.
String varStr = editextContact.getText().toString();
//int VarCount = editextContact.getText().length();
int countStringsSeperatedByComma = varStr.split(",").length;
String convet=String.valueOf(countStringsSeperatedByComma);
textViewConCount.setText(varStr);
if (varStr.length() == 0){
textViewConCount.setText("0");
}else {
textViewConCount.setText(convet);
}

Deleting a word in a String/String Array

So if you are adding in a string, you can just add them via += method(the one i know and using atm). but how can you delete a word in a string/string array?
example: i have a string
String="Monday,Tuesday,Wednesday"
how do you make it into
String="Monday,Wednesday"
any help please?

You could use the replace method.
String sentence = "Monday,Tuesday,Wednesday";
String replaced = sentence.replace("Tuesday,", "");

its easy
just use
yourString = yourString.replaceAll("the text to replace", ""); //the second "" show empty string so the text will get replace by empty string
finally yourString will contain the text u desire Thats it :)

You can use the "public String replace(char oldChar, char newChar)" method if you want to remove "Tuesday" and not the second element
https://stackoverflow.com/questions/16702357/how-to-replace-a-substring-of-a-string

I think, i will use it for simplicity otherwise go to other suggested answer...
Use Arraylist for storing days:
ArrayList<String> days = new ArrayList<String>();
days.add("Monday");
days.add("Tuesday");
days.add("Wednesday");
Use it for creating days string:
public String getDays() {
String daysString = "";
for (int i = 0; i < days.size(); i++) {
if (i != 0)
daysString += ", ";
daysString += days.get(i);
}
return daysString;
}
And whenever you want to remove use
days.remove(1);
or
days.remove("Tuesday");
then again call getDays();
IInd Method if you want to use only string:
String list = "Monday,Tuesday,Wednesday";
System.out.println("New String : " + removeAtIndex(list, 1));
and
public String removeAtIndex(String string, int index) {
int currentPointer = 0;
int lastPointer = string.indexOf(",");
while (index != 0) {
currentPointer = string.indexOf(',', currentPointer) + 1;
lastPointer = string.indexOf(',', lastPointer + 1);
index--;
}
String subString = string.substring(currentPointer,
lastPointer == -1 ? string.length() : lastPointer);
return string.replace((currentPointer != 0 ? "," : "") + subString
+ (currentPointer == 0 ? "," : ""), "");
}

Something like this using a regular expression:
String contents = "Monday,Tuesday,Wednesday";
contents = contents.replaceAll("[\\,]+Tuesday|^Tuesday[\\,]*", "");

How to replace the word in the string by using replace in Android?

I want to replace one word in the String by using substring. But it seen didn't work.
for example: The string is 0000 , and I want to replace the first word from 0 to 1.
It should be 1000. but it doesn't.
The code is like the following
String WorkStatus = "0000";
if(WorkStatus.substring(0, 1).matches("0"))
{
WorkStatus.substring(0, 1).replace("0", "1");
Log.d(TAG, "WorkStatus.substring(0, 1) = " + WorkStatus.substring(0, 1) + "\n");
Log.d(TAG, "WorkStatus = " + WorkStatus + "\n");
}
It didn't work , the string always show 0000. And what I want is "1000"
Do I missing something ?

use this
String WorkStatus = "0000";
//You use matches, while you might as well use equals
if (WorkStatus.substring(0, 1).equals("0")) {
//reassign workstatus to workstatus where the first entry is a '1' + the last three chars "000"
WorkStatus = WorkStatus.substring(0, 1).replace("0", "1") + WorkStatus.substring(1, WorkStatus.length());
Log.d(TAG, "WorkStatus.substring(0, 1) = " + WorkStatus.substring(0, 1) + "\n");
Log.d(TAG, "WorkStatus = " + WorkStatus + "\n");
}
You didnt assign the modified string to WorkStatus
Another possibility is converting the string to a char[] and replacing the index, instead of working with substrings.
String WorkStatus = "0000";
char[] chars = WorkStatus.toCharArray();
if (chars[0] == '0') {
chars[0] = '1';
WorkStatus = new String(chars);
}
If you want other chars to become 1 instead of zero, alter the chars[0] into chars[index], where index is the index you want to change from 0 to 1
Or, even easier, use a StringBuilder:
int yourIndex = 2; //your index which you want to check for 0 and change to 1
StringBuilder sb = new StringBuilder("0000");
if (sb.charAt(yourIndex) == '0')
sb.setCharAt(yourIndex, '1');
WorkStatus = sb.toString();

method replace has a return value of the string after replaced
you shuold resign the result to the String
WorkStatus=WorkStatus.substring(0, 1).replace("0", "1")+ WorkStatus.substring(1, WorkStatus.length();

if you asign it to a new variable like the below code, you can get what you needed.
String newWorkStatus=WorkStatus.substring(0, 1).replace("0", "1")+WorkStatus.substring(1);
Log.d("LOG", "WorkStatus.substring(0, 1) = " + WorkStatus.substring(0, 1) + "\n");
Log.d("LOG", "WorkStatus = " + WorkStatus + "\n");
Log.d("LOG", "New WorkStatus = " + newWorkStatus + "\n");

WorkStatus.substring(0, 1).replace("0", "1"); returns 1, you should use StringBuilder instead of String.
My solution:
StringBuilder WorkStatus = new StringBuilder("0000");
int pos = WorkStatus.indexOf("0", 0);
if (pos != -1) {
WorkStatus.replace(pos, pos + 1, "1");
}
System.out.print(WorkStatus);

How can I effectively replace one or more characters

I have a String separated by commas as follows
1,2,4,6,8,11,14,15,16,17,18
This string is generated upon user input. Suppose the user wants to remove any of the numbers, I have to rebuild the string without the specified number.
If the current string is:
1,2,4,6,8,11,14,15,16,17,18
User intents to remove 1, the final string has to be:
2,4,6,8,11,14,15,16,17,18
I tried to achieve this using the following code:
//String num will be the number to be removed
old = tv.getText().toString(); //old string
newString = old.replace(num+",",""); //will be the new string
This might be working sometimes but it is sure that it won't work for the above example I have shown, if I try to remove the 1, it also removes the last part of 11, because there also exists 1.

well you can use this. Its the most simplest approach i can think of:
//String num will be the number to be removed
old=","+tv.getText().toString()+",";//old string commas added to remove trailing entries
newString=old.replace(","+num+",",",");// will be the new string
newString=newString.substring(1,newString.length()-1); // removing the extra commas added
This would work for what you want to do. I have added a comma at the start and end of your string so that you can also remove the first and last entries too.

You can split the string first and check for the number where you append those value that is not equivalent to the number that will get deleted;
sample:
String formated = "1,2,4,6,8,11,14,15,16,17,18";
String []s = formated.split(",");
StringBuilder newS = new StringBuilder();
for(String s2 : s)
{
if(!s2.equals("1"))
newS.append(s2 + ",");
}
if(newS.length() >= 1)
newS.deleteCharAt(newS.length() - 1);
System.out.println(newS);
result:
2,4,6,8,11,14,15,16,17,18

static public String removeItemFromCommaDelimitedString(String str, String item)
{
StringBuilder builder = new StringBuilder();
int count = 0;
String [] splits = str.split(",");
for (String s : splits)
{
if (item.equals(s) == false)
{
if (count != 0)
{
builder.append(',');
}
builder.append(s);
count++;
}
}
return builder.toString();
}

String old = "1,2,4,6,8,11,14,15,16,17,18";
int num = 11;
String toRemove = "," + num + "," ;
String oldString = "," + old + ",";
int index = oldString.indexOf(toRemove);
System.out.println(index);
String newString = null;
if(index > old.length() - toRemove.length() + 1){
newString = old.substring(0, index - 1);
}else{
newString = old.substring(0, index) + old.substring(index + toRemove.length() -1 , old.length());
}
System.out.println(newString);

Android basic math in textview

I am trying to add two numbers and display them in the textview using this code. The problem here is that it doesn't add the numbers, it just displays the entire string.
CharSequence fnum, snum, symbol;
final TextView CalTextBox = (TextView) findViewById(R.id.MainTextview);
symbol = "+"; // addition selected
fnum = CalTextBox.getText(); // store number into fnum
snum = CalTextBox.getText(); //new number will be added in the code and be stored into snum
CalTextBox.setText(""); // delete whats in the text box
CalTextBox.setText(snum + "" + symbol + "" + fnum); // add two numbers

Well, the '+' operator performs concatenation if used on strings (like in this case). To perform a math operation, you have to convert them to numbers first. I think you can use this:
// Convert the 2 String to integer values
int first = Integer.valueOf(fnum);
int second = Integer.valueOf(snum);
// Compute the sum
int sum = first + second;
// Create the String you can use to display in the TextView
String textToDisplay = String.valueOf(sum);

snum = "2";
fnum = "3";
symbol = "+";
snum + "" + symbol + "" + fnum = "2+3"
Instead you should convert String into integer or double and make appropriate controls such as null or empty, or non-numeric then,
int result = Integer.parseInt(snum) + Integer.parseInt(fnum);
CalTextBox.setText("" + result);

For mathematical operations is best to use int, long or double variable types. Instead of CharSequence use for example int.
to get integer (int) from String (text) use:
int fnum, snum, symbol;
int fnum = Integer.parseInt("10"); or
fnum = Integer.parseInt(CalTextBox.getText());
CalTextBox.setText("" + (snum + symbol + fnum));