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]);
Related
now i've got simple setter and getter of string array. I want to use setter to put some retrevied json info + same text to array. When i use belowe code:
met.setPlacepic(new String[]{"http://dfsdfsdfsf/" + json.getString("source")});
it looks like setter put only one string to array, despite there is many more data.
Declaration is simple
public String[] placepic
and the setter is also simple:
public void setPlacepic(String[] placepic) {
this.placepic = placepic;
}
Anybody knows reason of this?
If the number of strings is fixed (you know exactly how many element you would have in the array), then you could use String Arrays:
String[] placepic = new String[20]; //20 strings
//Then, in your loop:
placepic[i] = yourData;
If you do NOT know how many strings in your data, You should use List:
List<String> placepicList= new ArrayList<String>();
//Then, in your loop:
placepicList.add(yourData);
//Then after the loop, you get the array
String[] placepic = placepicList.toArray(new String[placepicList.size()]);
im using MultiSelectListPreference and the values save on array..
How can read??
SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(this);
Set<String> a = pref.getStringSet("tabs", null);
for ( int i = 0; i < a.size(); i++) {
Log.d("salida", a[i]);
}
i get this error: The type of the expression must be an array type but it resolved to Set
You want to use the Set, and since it isn't an array, the square brackets ([])are cannot be used to access indexes.
To easily read the values from the Set,use the enhanced for loop:
for (String str: a){
Log.d("salida", str);
}
If you want to remove items from that Set as you loop through, you will have to use an Iterator, as shown in this answer.
Alternatively, if you want an array, you can use Set#toArray():
String [] prefStrings = a.toArray(new String[a.size()]);
Then you can use the square brackets (prefStrings[position]) to access an index.
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
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();
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).