I have to create a password and I believe that I can do it, however I am stumped at the very beginning. I have 3 strings of characters, I would like to randomly select one of these three strings. Does anybody know how to do it?
Dim sLowerCase As String = "qwertyuiopasdfghjklzxcvbnm"
Dim sUpperCase As String = "MNBVCXZLKJHGFDSAPOIUYTREWQ"
Dim sNumbers As String = "1234567890"
So I want to randomly select one of these three strings
I suggest you to use ListOf string instead for this. you can code like the following;
Dim listofStrings As New List(Of String) ' Declaration of list of strings
listofStrings.Add("qwertyuiopasdfghjklzxcvbnm") 'assign values to the list
listofStrings.Add("MNBVCXZLKJHGFDSAPOIUYTREWQ")
listofStrings.Add("1234567890")
Dim rnd As New Random
Dim randomString As String = listofStrings.Item(rnd.Next(0, 3))'select random string from the list
it will generate random numbers between 0 and 2 hence it will help you to select random string from the list of strings based on index referenced by the random number
The below code will help you generate a random number and then pick up the string at that position in the array
string[] arr= {"qwertyuiopasdfghjklzxcvbnm","MNBVCXZLKJHGFDSAPOIUYTREWQ","1234567890"};
Random rnd = new Random();
int cnt = rnd.Next(2);
string r = arr[cnt];
Related
I am working in VB.net to help teach myself the language. The program I am creating requires the input of two strings, both of which I would like to add to an ArrayList in a specific way.
For the first input, say Hello World, I would like to capitalize the letters and input it into a list of the form:
InputCharacterList = {"H","E","L","L","O"," ","W","O","R","L","D"}
After this I would then like to convert this into an ArrayList of Integers using the characters ASCII values, so:
IntegerList = {72,69,76,76,79,32,87,79,82,76,68}
Note: I want to capitalize all the letters because I want to guarantee that my IntegerList contains only integers with 2 numbers.
Now for the next part, I pretty much want to do the reverse. So if the input is a string: 7269767679, I want to create an ArrayList of Integers such as:
InputIntegerList = {72,69,76,76,79}
I then want to convert it back into an ArrayList using ASCII values, so:
CharacterList = {"H","E","L","L","O"}
This second way seems to be much more difficult to me. I cannot easily see how to step through a string two values at a time. Nevertheless I cannot easily see how to do either approach in VB.net
Thanks for the help!
Dim sInput As String = "Hello World"
Dim sOutput As String
Dim AL_c As New ArrayList
Dim AL_b As New ArrayList
' Add Input to Arraylist
AL_c.AddRange(sInput.ToUpper.ToArray)
' Add Bytes to Arralist
For Each c As Char In AL_c
AL_b.Add(Convert.ToByte(c))
Next
sOutput = String.Concat(AL_b.ToArray)
' Reverse
sInput = "7269767679"
Dim i As Integer
Dim cTemp As Char
AL_c.Clear()
AL_b.Clear()
i = sInput.Length
' Add Bytes to Arraylist
For Each c As Char In sInput.ToArray
If (i And 1) = 0 Then
cTemp = c
Else
AL_b.Add(CByte(cTemp & c))
End If
i -= 1
Next
' Add Characters to Arraylist
For Each b As Byte In AL_b
AL_c.Add(Chr(b))
Next
' Create Output string = "HELLO"
sOutput = String.Concat(AL_c.ToArray)
I am stuck here. Spent hours trying many different approaches but nothing is working
I have an array that holds text that looks like this
4456|4450|17
4466|4430|18
4446|4420|19
4436|4410|20
The separator is a pica ("|").
What I am trying to do is run through the array and extract the first two columns in separate strings to compare the values, look for the max, and min.
I am trying to end up with a string like this
4456,4466,4446,4436
Here is the solution:
Dim source As String = prices
Dim stringSeparators() As String = {vbCrLf}
Dim result() As String
result = source.Split(stringSeparators,
StringSplitOptions.RemoveEmptyEntries)
Dim fString As String = String.Join(Of String)(", ", result.Cast(Of String).Select(Of String)(Function(x) x.Split("|")(0)))
MsgBox(fString)
Let's take your example below...
4456|4450|17
4466|4430|18
4446|4420|19
4436|4410|20
prices = [the array shown above]
For Each i As String In prices
high = (i.Split("|"))(0)
highs = highs & highs1 & ","
MsgBox(highs)
Next
The reason you are getting 4,4,5,6,,4,4,5,0,,1,7 is because for each string you are splitting on the | and then taking the first character adding a comma to it.
If you want to get the first column or index whatever you want to call it before the | you need to loop through each string in that array and select out the values...
'this is my test array...
Dim arr As New ArrayList From {"4456|4450|17", "4466|4430|18", "4446|4420|19", "4436|4410|20"}
Now we can use a String.Join function, cast the array for each item as a string and finally select the first item on the split. This will get every item before the | and put them in a string separated with a comma.
Dim fString As String = String.Join(Of String)(", ", arr.Cast(Of String).Select(Of String)(Function(x) x.Split("|")(0)))
If you want the second section select the 1st index as arrays start at 0...
Dim sString As String = String.Join(Of String)(", ", arr.Cast(Of String).Select(Of String)(Function(x) x.Split("|")(1)))
Here is my screenshot of the outputs...
How can I select any random string from a given list of strings? Example:
List1: banana, apple, pineapple, mango, dragon-fruit
List2: 10.2.0.212, 10.4.0.221, 10.2.0.223
When I call some function like randomize(List1) = somevar then it will just take any string from that particular list. The result in somevar will be totally random. How can it be done? Thank you very much :)
Use Random
Dim rnd = new Random()
Dim randomFruit = List1(rnd.Next(0, List1.Count))
Note that you have to reuse the random instance if you want to execute this code in a loop. Otherwise the values would be repeating since random is initialized with the current timestamp.
So this works:
Dim rnd = new Random()
For i As Int32 = 1 To 10
Dim randomFruit = List1(rnd.Next(0, List1.Count))
Console.WriteLine(randomFruit)
Next
since always the same random instance is used.
But this won't work:
For i As Int32 = 1 To 10
Dim rnd = new Random()
Dim randomFruit = List1(rnd.Next(0, List1.Count))
Console.WriteLine(randomFruit)
Next
Create a List of Strings.
Create a random number generator: Random class
Call Random number generator's NextInt() method with List.Count as the upper bound.
Return List[NextInt(List.count)].
Job done :)
Generate a random number between 1 and the size of the list, and use that as an index?
Try this:
Public Function randomize(ByVal lst As ICollection) As Object
Dim rdm As New Random()
Dim auxLst As New List(Of Object)(lst)
Return auxLst(rdm.Next(0, lst.Count))
End Function
Or just for string lists:
Public Function randomize(ByVal lst As ICollection(Of String)) As String
Dim rdm As New Random()
Dim auxLst As New List(Of String)(lst)
Return auxLst(rdm.Next(0, lst.Count))
End Function
You could try this, this is a simple loop to pick every item from a list, but in a random manner:
Dim Rand As New Random
For C = 0 to LIST.Count - 1 'Replace LIST with the collection name
Dim RandomItem As STRING = LIST(Rand.Next(0, LIST.Count - 1)) 'Change the item type if needed (STRING)
'' YOUR CODE HERE TO USE THE VARIABLE NewItem ''
Next
I have a file txt file that holds 3 values each seperated by a space how can i assign each value to its own variable and use that for other things?
as example the numbers might be displayed in the text file as:
-1100.02 -1958.19 0.0
Translating Marco’s C# code to VB:
Dim s As String = File.ReadAllText(filename)
Dim nums As String() = s.Split(" "c)
To get numbers, you need to parse the strings separately. You can use Linq to do this:
Dim numbers As Double() = From num In nums Select Double.Parse(num)
In C#:
string s = File.ReadAllText(filename);
string[] nums = s.Split(' ');
So you can access nums[index] where index should be between 0 and 2.
Note that you MUST check if everything went ok...
If you need you can also try:
foreach (string num in nums)
{
double d = double.Parse(num);
// Here you can do what you want with d
}
Try this:
Dim line as String = "-1100.02 -1958.19 0.0"
Dim values() as Double = Array.ConvertAll(line.Split(New Char() { " "c }, StringSplitOptions.RemoveEmotyEntries), AddressOf Convert.ToDouble)
This will result in values being filled with numbers from the input string (assuming a set of valid numbers on each line).
dim strSplitted() as string = Line.split(" "c)
' strSplitted(0), strSplitted(1) and strSplitted(2) will hold the values.
Line is the line in the file ofcourse :-)
update: code updated according to comments.
I have this string that shall come in from another file. The string has maximum length of 102 digits. I need to compare the string with numbers in a pair and delete those from that string.
e.g - 6125223659587412563265... till 102
numbers that compare with this string-
first set - 61
new string = 25223659587412563265
second set - 36
new string = 252259587412563265
and so on. the set of numbers shall go to maximum of 51 pairs = 102, which shall give an end result of string = ""
How can i achieve this in a loop?
this is not answer, this is editing the question. i dont know why but the edit button just vaniashed so i have to edit question here.
No duplicates will ever be in this string. and in the end when compares are done, i want to see what numbers are left in pairs.
Dim input As String = "6125223659587412563265"
Dim targets As String() = {"61", "36"}
For Each target As String In targets
input = input.Replace(target, "")
Next
Debug.Assert(input = "252259587412563265")
Here is a simple solution. You will need to add your pairs to the List(Of String) and also initialize input to the string you want to alter.
Dim pairs As New List(Of String)()
Dim input As String = String.Empty
For Each pair As String In pairs
input = input.Replace(pair, String.Empty)
Next