Java String.replace() - replaces more than just the substring I specify?

As per this CodingBat problem I am trying to do the following:

Given a string, if the first or last chars are 'x', return the string without those 'x' chars, and otherwise return the string unchanged.

My code:

public String withoutX(String str) {
    if (str.startsWith("x")) {
        str = str.replace(str.substring(0, 1), "");
    }
    if (str.endsWith("x")) {
        str = str.replace(str.substring(str.length()-1), "");
    }
    return str;
}

This code replaces ALL the x characters in the string, rather than just the first and last. Why does this happen, and what would be a good way to solve it?

I have json that looks like the following

{  
   "tiles":[  
      {  
         "header":"Manual",
         "subheader":"Login",
         "summary1_label":"",
         "summary2_label":"",
         "summary3_label":"",
         "summary4_label":"",
         "summary1_value":"",
         "summary2_value":"",
         "summary3_value":"",
         "summary4_value":"",
         "iconUrl":"http://ift.tt/1C39tpD"
      },
      {  
         "header":"NewUser",
         "subheader":"Login",
         "summary1_label":"",
         "summary2_label":"",
         "summary3_label":"",
         "summary4_label":"",
         "summary1_value":"",
         "summary2_value":"",
         "summary3_value":"",
         "summary4_value":"",
         "iconUrl":"http://ift.tt/1OVVAUg"
      },
      {  
         "header":"Facebook",
         "subheader":"Login",
         "summary1_label":"",
         "summary2_label":"",
         "summary3_label":"",
         "summary4_label":"",
         "summary1_value":"",
         "summary2_value":"",
         "summary3_value":"",
         "summary4_value":"",
         "iconUrl":"http://ift.tt/1C39tpF"
      }
   ]
}

I cast this as a JsonObject and send it to a reformating method. in that method i do the following

public ArrayList<String[]> formatHttpResponse_SummaryTile(JSONObject json) throws JSONException {
    ArrayList<String[]> arrayList_summary = new ArrayList<String[]>();
    JSONArray tilesArray = json.getJSONArray("tiles");
    //JSONObject allTilesData = json.getJSONObject("tiles");
    for (int i=0; i<tilesArray.length(); i++)
    {
        //JSONObject thisJsonObject = tilesArray.getJSONObject(i);
        JSONArray thisJsonArray = tilesArray.getJSONArray(i);
        String[] thisStringArray = new String[thisJsonArray.length()];
        for (int j=0; j<thisJsonArray.length(); j++)
        {
            thisStringArray[j]=thisJsonArray.getString(j);
        }
        arrayList_summary.add(thisStringArray);
    }
    return arrayList_summary;
}

As you can see i create an array list then cycle through my jsonObjects 3 children. Now the problem is that i want to convert the children to String[][ but my code bugs out at JSONArray thisJsonArray = tilesArray.getJSONArray(i); as it isnt a jsonArray.

Any idea how i can get the children above into 3 string arrays all added to a arrayList Is there a more efficent, straight cast i can do?

Counting String objects created by Java code

How many String objects have been created by the following code?

String x = new String("xyz");
String y = "abc";
x = x + y;

I have seen on another site some say that this line of code creates a 3 objects and some says this line of code create a 4 objects. So let me know how many objects created after this line of code executes.

How do I convert a deliminated file in base - R into seperate columns without creating a list?

I currently do this using the following code

write(unlist(fieldList),"c:/temp/test.txt") temp1<-cbind(fieldList,read.delim("c:/temp/test.txt",sep=" ",header=FALSE))

but this is slow because it obliges the app to write data to temp file on disk.

I have tried strsplit function and "qdap" library but they both create lists. I need to be able to manipulate the columns separately

NewColumn <- substr(temp1[,5],1,1)

PHP how to count the length of each word in the text file

i need some help. how to count the length of each word in the text file using PHP.

for example. there is the test.txt. and the contain is " hello everyone, i need some help." how to output the text and then count the length of each word，like:

array

hello => 5
everyone => 8
i => 1
need  => 4
some => 4
help => 4

i just start to learn php. so please explain the detail about the code what you write.

many thanks

split String in java from a list

Values in my list(collection) list[a,b,c,d]

Here is my String "select ?,? from table where ?=?"

I want to fill every question mark with these values in order and in the last result should be "select a,b from table where c=d

Python putting r before unicode string variable

For static strings, putting an r in front of the string would give the raw string (e.g. r'some \' string'). Since it is not possible to put r in front of a string variable, what is the minimal approach to dynamically convert a string variable to its raw form? Should I manually substitute all backslashes with double backslashes?

str_var = u"some text with escapes e.g. \( \' \)"
raw_str_var = ???