So, I've been looking around SO and a few other sites for a solid method of converting hex values embedded in normal strings (eg. The '/' are in the string as '\x2F') and wasn't able to find a solution that specifically fit my needs.
What I ended up doing was writing a bit of code myself to handle this:
for (int i = 0; i < 128; i++)
{
string hexString = i.ToString("X").PadLeft(2, '0');
string searchString = #"\x" + hexString;
if (response.Contains(searchString))
{
int charValue = Convert.ToInt32(hexString, 16);
string character = Char.ConvertFromUtf32(charValue);
response = response.Replace(searchString, character);
}
}
My question is this:
Is this a good way of going about it?
Any perticular drawbacks to me using this?
The purpose of this code is to take a string like:
"previous content...http:\x2F\x2Fwww.google.com...after content"
and convert it to:
"previous content...http://www.google.com...after content"
Related
Okay, so what does the SET stand for in the second line? Why is the second string in<>, ?
public Weighted(In in, String delimiter) {
st = new ST<String, SET<String>>();
while (!in.isEmpty()) {
String line = in.readLine();
String[] names = line.split(delimiter);
for (int i = 1; i < names.length; i++) {
addEdge(names[0], names[i]);
}
}
}
With the little information you gave, I will assume that SET is an abstract data type. An abstract data type can store any values without any particular order and with no duplicates. By telling <String> after SET you are telling you want to store Strings inside your SET.
You can learn more about SETs here: https://en.wikipedia.org/wiki/Set_(abstract_data_type)
I have a string.
string str = "TTFTTFFTTTTF";
How can I break this string and add character ","?
result should be- TTF,TTF,FTT,TTF
You could use String.Join after you've grouped by 3-chars:
var groups = str.Select((c, ix) => new { Char = c, Index = ix })
.GroupBy(x => x.Index / 3)
.Select(g => String.Concat(g.Select(x => x.Char)));
string result = string.Join(",", groups);
Since you're new to programming. That's a LINQ query so you need to add using System.Linq to the top of your code file.
The Select extension method creates an anonymous type containing the char and the index of each char.
GroupBy groups them by the result of index / 3 which is an integer division that truncates decimal places. That's why you create groups of three.
String.Concat creates a string from the 3 characters.
String.Join concatenates them and inserts a comma delimiter between each.
Here is a really simple solution using StringBuilder
var stringBuilder = new StringBuilder();
for (int i = 0; i < str.Length; i += 3)
{
stringBuilder.AppendFormat("{0},", str.Substring(i, 3));
}
stringBuilder.Length -= 1;
str = stringBuilder.ToString();
I'm not sure if the following is better.
stringBuilder.Append(str.Substring(i, 3)).Append(',');
I would suggest to avoid LINQ in this case as it will perform a lot more operations and this is a fairly simple task.
You can use insert
Insert places one string into another. This forms a new string in your C# program. We use the string Insert method to place one string in the middle of another one—or at any other position.
Tip 1:
We can insert one string at any index into another. IndexOf can return a suitable index.
Tip 2:
Insert can be used to concatenate strings. But this is less efficient—concat, as with + is faster.
for(int i=3;i<=str.Length - 1;i+=4)
{
str=str.Insert(i,",");
}
Does this work? I'm trying to print a message in this.
char[] tempMessage = message.toCharArray();
String[] message2 = message.split(" ");
Integer.toString(number).toCharArray();
for(int x = 0; x<newMessage.length; x++)
{
}
Although its better to use a StringBuilder, I can show it using String(s).
String[] strArr = "hello world".split("\\s+");
String s = String.valueOf(strArr[0].charAt(0))+strArr[0].length()+String.valueOf(strArr[1].charAt(0))+strArr[1].length();
Output : h5w5
String[] message2 = message.split("\\s+");
String output = "";
for(int i = 0; i < message2.length; i++)
{
output += "" + message2[i].charAt(0) + message2[i].length();
}
//output has output string.
TheLostMind's solution is already good, but I think it needs a solution for Strings of arbitrary length.
String outputString = "";
for(String x : message.split("\\s+"))
{
outputString = outputString.concat(x.charAt(0) + x.length());
}
As stated in the comments, this solution is very similiar to brso05's solution. The difference is in using the :-Operator in the for-loop. It's shorter and IMHO easier to understand, as it says 'for each String in the resulting array'.
Also, using the concat()-function is considered safer in my work environment.
I strings in the format of name:key:dataLength:data and these strings can often be chained together. for example "aNum:n:4:9879aBool:b:1:taString:s:2:Hi" this would map to an object something like:
{
aNum: 9879,
aBool: true,
aString: "Hi"
}
I have a method for parsing a string in this format but I'm not sure whether it's use of substring is the most efficient way of pprocessing the string, is there a more efficient way of processing strings in this fashion (repeatedly chopping off the front section):
Map<string, dynamic> fromString(String s){
Map<String, dynamic> _internal = new Map();
int start = 0;
while(start < s.length){
int end;
List<String> parts = new List<String>(); //0 is name, 1 is key, 2 is data length, 3 is data
for(var i = 0; i < 4; i++){
end = i < 3 ? s.indexOf(':') : num.parse(parts[2]);
parts[i] = s.substring(start, end);
start = i < 3 ? end + 1 : end;
}
var tranType = _tranTypesByKey[parts[1]]; //this is just a map to an object which has a function that can convert the data section of the string into an object
_internal[parts[0]] = tranType._fromStr(parts[3]);
}
return _internal;
}
I would try s.split(':') and process the resulting list.
If you do a lot of such operations you should consider creating benchmarks tests, try different techniques and compare them.
If you would still need this line
s = i < 3 ? s.substring(idx + 1) : s.substring(idx);
I would avoid creating a new substring in each iteration but instead just keep track of the next position.
You have to decide how important performance is relative to readability and maintainability of the code.
That said, you should not be cutting off the head of the string repeatedly. That is guaranteed to be inefficient - it'll take time that is quadratic in the number of records in your string, just creating those tail strings.
For parsing each field, you can avoid doing substrings on the length and type fields. For the length field, you can build the number yourself:
int index = ...;
// index points to first digit of length.
int length = 0;
int charCode = source.codeUnitAt(index++);
while (charCode != CHAR_COLON) {
length = 10 * length + charCode - 0x30;
charCode = source.codeUnitAt(index++);
}
// index points to the first character of content.
Since lengths are usually small integers (less than 2<<31), this is likely to be more efficient than creating a substring and calling int.parse.
The type field is a single ASCII character, so you could use codeUnitAt to get its ASCII value instead of creating a single-character string (and then your content interpretation lookup will need to switch on character code instead of character string).
For parsing content, you could pass the source string, start index and length instead of creating a substring. Then the boolean parser can also just read the code unit instead of the singleton character string, the string parser can just make the substring, and the number parser will likely have to make a substring too and call double.parse.
It would be convenient if Dart had a double.parseSubstring(source, [int from = 0, int to]) that could parse a substring as a double without creating the substring.
I am trying to store the string value into vector. And then after storing I want to store in string one by one. In first step split the sting by "," and store into vector. And again try to retrive and get into string.
My code:
CString sAssocVal = "test1, test2, test3";
istringstream ss( sAssocVal.GetBuffer(sAssocVal.GetLength()) );
vector<string> words;
string token;
while( std::getline(ss, token, ',') )
{
words.push_back( token );
}
Try to again retrive from vector:
for(int i = 0; i<words.size(); i++)
std::string st= words[i];
But the value of st is getting NULL always.
where I am missing some thing.
AFAIK the problem is the istringstream initialization, a small modification makes your example work:
http://coliru.stacked-crooked.com/a/698818655cbba4e7
You could first convert CString to std::string, there are a lot of topics about that problem
I resolved this is by using this code.
CString st;
for(int i = 0; i<words.size(); i++)
st= words[i].c_str();