Remove Last element from a Character Array in Android? - android

What i Have: At present i have a String variable i-e:
String str_StoreValue;
I have appended it with some string values and converted it into a Character Array by doing this:
char[] ch_TestArray = str_StoreValue.toCharArray();
What i want: i want to remove the last element of this char[] ch_TestArray.
Can somebody help me out. I'm new to android.

This is just easier:
char[] ch_TestArray = str_StoreValue.substring(0, str_StoreValue.length()-1).toCharArray();

Related

How can i get few characters from String?

I want to retrieve few characters from string i.e., String data on the basis of first colon (:) used in string . The String data possibilities are,
String data = "smsto:....."
String data = "MECARD:....."
String data = "geo:....."
String data = "tel:....."
String data = "MATMSG:....."
I want to make a generic String lets say,
String type = "characters up to first colon"
So i do not have to create String type for every possibility and i can call intents according to the type
It looks like you want the scheme of a uri. You can use Uri.parse(data).getScheme(). This will return smsto, MECARD, geo, tel etc...
Check out the Developers site: http://developer.android.com/reference/android/net/Uri.html#getScheme()
Note: #Alessandro's method is probably more efficient. I just got that one off the top of my head.
You can use this to get characters up to first ':':
String[] parts = data.split(":");
String beforeColon = parts[0];
// do whatever with beforeColon
But I don't see what your purpose is, which would help giving you a better solution.
You should use the method indexOf - with that you can get the index of a certain char. Then you retrieve the substring starting from that index. For example:
int index = string.indexOf(':');
String substring = string.substring(index + 1);

Convert String to Character Array? and Retrieve

How do I create a character array from a string? for example, say I have the string "Hello World"
How would I convert it to a character array?
Once converted, how do I retrieve each individual letter one by one?
My code:
public Character[] toCharacterArray(String s) {
if (s == null) {
return null;
}
Character[] array = new Character[s.length()];
for (int i = 0; i < s.length(); i++) {
array[i] = new Character(s.charAt(i));
}
return array;
}
Now if the above was implemented, how would I retrieve the returned character and how would I output it in an edit text box? using outputBox.setText(); maybe?
you can convert a String to Char array simply using toCharArray() method...
char[] charArray = string.toCharArray();
So, your updated method should be as follows...
public char[] toCharacterArray(String s) {
char[] array = s.toCharArray();
return array;
}
This appears to be a homework question, so I'm only going to give hints.
1) How would I convert it to a charterer array?
You've already done that!! However:
it would possibly be better if either you used a char[] instead of a Character[], and
if you do continue to use a Character, then it is better to use Character.valueOf(...) instead of new Character(...).
2) once converted how do I retrieve each and individual letter 1 by 1?
Use a for loop. It is one of the standard Java statements. Refer to your Java textbook, tutorial, lecture notes ...
... how would i output it in an edit text box... using outputbox.setText(????)
Use static Character.toString(char), or Character.toString() to create a String, depending on the type you have used. You can then pass that as an argument to setText ...
For details of the methods I mentioned above, read the javadocs.
Convert the string to a simple char array like this:
String test = "hello";
char[] chars = test.toCharArray();
Then you can output any particular char in the array like this:
outputbox.setText(String.valueOf(chars[i]);

how to remove a string from arraylist of strings, ANDROID

I created an arraylist of strings
List<String> textArray = new ArrayList<String>();
and then I added the strings(which I am getting from edittext) to textArray as follows
String text = editText1.getText().toString();
textArray.add(text);
Now I created a button and need to remove the string from the array when the button is clicked.But i dont know what to do.
I know for arrays of bitmaps we clear a bitmap from array using recycle but Please suggest me how to remove or clear the string from arraylist.
You can call one of:
to remove all entries
textArray.clear();
to remove from a specific position (e.g. first item)
textArray.remove(0);
to remove a specific string (that equals yours)
textArray.remove("myString");
Try this..
Getting position from the textArray array list
int pos = textArray.indexOf(text);
and then remove from the string position
textArray.remove(pos);
because we cannot directly remove the string. we can remove the string contains position.
You can do it with more then one way as per your need.
textArray.clear();
It will clear whole ArrayList.
If you want to remove only some specifis data from index then,
textArray.remove(INDEX TO REMOVE);
Try This
String text = editText1.getText().toString();
textArray.add(text);
to remove
textArray.remove(text);

Extract text from String

I have one String and into this string I have a url between two characters # such as "Hello world #http://thisurl# my name is Pippo" I want to take the url (http://thisurl) between two #.
How can I do ? Thanks
String data[] = str.split("#"); //spilliting string and taking into array
ArrayList<String> urlList = new ArrayList<String>();
for (int i = 0; i < data.length; i++) {
if(data[i].contains("http://"))
urlList.add(data[i]); //if string contains "http://" it means it is url save int list.
}
now you can get all uls from urlList.get(i) method.
this urlList will give you all the urls available in the string. I dint applied any null or other check. Apply it and try. If want something else try modifying content and checks.
Try String.split(). You really should be trying to google these things first.
here is an example - http://www.java-examples.com/java-string-split-example
The split method divides a string into several strings and store them into an array using a delimiter which can be defined by you.
the second element in the resulting array will be your URL

Android String Array Manipulation

I have a lengthy string in my Android program.
What I need is, I need to split each word of that string and copy that each word to a new String Array.
For eg: If the string is "I did android program" and the string array is named my_array then each index should contain values like:
my_array[0] = I
my_array[1] = did
my_array[2] = Android
my_array[3] = Program
A part of program which I did looks like this:
StringTokenizer st = new StringTokenizer(result,"|");
Toast.makeText(appointment.this, st.nextToken(), Toast.LENGTH_SHORT).show();
while(st.hasMoreTokens())
{
String n = (String)st.nextToken();
services1[i] = n;
Toast.makeText(appointment.this, st.nextToken(), Toast.LENGTH_SHORT).show();
}
Can any one please suggest some ideas..
Why not use String.split() ?
You can simply do
String[] my_array = myStr.split("\\s+");
Since '|' is a special character in regular expression, we need to escape it.
for(String token : result.split("\\|"))
{
Toast.makeText(appointment.this, token, Toast.LENGTH_SHORT).show();
}
You can use String.split or Android's TextUtils.split if you need to return [] when the string to split is empty.
From the StringTokenizer API docs:
StringTokenizer is a legacy class that
is retained for compatibility reasons
although its use is discouraged in new
code. It is recommended that anyone
seeking this functionality use the
split method of String or the
java.util.regex package instead.
Since String is a final class, it is by default immutable, which means you cannot make changes to your strings. If you try, a new object will be created, not the same object modified. Therefore if you know in advance that you are going to need to manipulate a String, it is wise to start with a StringBuilder class. There is also StringBuffer for handling threads. Within StringBuilder there are methods like substring():
substring(int start)
Returns a new String that contains a subsequence of characters currently contained in this character sequence.
or getChars():
getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)
Characters are copied from this sequence into the destination character array dst.
or delete():
delete(int start, int end)
Removes the characters in a substring of this sequence.
Then if you really need it to be a String in the end, use the String constructor(s)
String(StringBuilder builder)
Allocates a new string that contains the sequence of characters currently contained in the string builder argument.
or
String(StringBuffer buffer)
Allocates a new string that contains the sequence of characters currently contained in the string buffer argument.
Although to understand when to use String methods and when to use StringBuilder, this link or this might help. (StringBuilder comes in handy with saving on memory).

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