How to count occurrences of a character in a string in Presto?

Dim i as Integer
Dim index As Integer
Dim count as Integer
Dim FoundByAscii(0 To 255) As Boolean
For i = 1 To Len(text)
    index = Asc(Mid$(text, i, 1))
    FoundByAscii(index) = True
Next i
count = 0
For i = 0 To 255
    If FoundByAscii(i) Then
        count = count + 1
    End If
Next i

   ' count spaces
    Dim asciiToSearchFor As Integer
    asciiToSearchFor = Asc(" ")
    For i = 1 To Len(text)
        If Asc(Mid$(text, i, 1)) = asciiToSearchFor Then count = count + 1 
    Next

#include <iostream> 
#include <string>
#include <conio.h> 

int main() 
{ 
    std::string a, b; 
    int count = 0; 

    std::cout << "Enter 1st String: "; 
    std::getline(std::cin, a); 
    std::cout << "Enter 2nd String: "; 
    std::getline(std::cin, b);

    std::string::size_type i = a.find(b);
    while (i != std::string::npos)
    {
        ++count;
        i = a.find(b, i+b.length());
    } 

    std::cout << "Output: " << count; 

    getch(); 
    return 0; 
} 

int count = 0;
String text = "sentence";
Pattern pat = Pattern.compile("e(?!$)");
Matcher m = pat.matcher(text);
while (m.find()) {
        count++;
}
System.out.println(count);

Sub Main()
    Dim text As String = "some random text"
    Dim charactersInfo = text.GroupBy(Function(c) c).ToDictionary(Function(p) p.Key, Function(p) p.Count())

    For Each p In charactersInfo
        Console.WriteLine("char:{0}  times:{1}", p.Key, p.Value)
    Next

    Console.ReadLine()
End Sub

sample.GroupBy(c => c).Select(c => new { Char = c.Key, Count = c.Count()});