Simply Tricky Codes

Today I am sharing with some unique but popular codes which are still being ask in interviews for fresh graduates. First I want to give you the list of those codes. (This is final release, perhaps it would grow with passage of time and technology)

1. Calculate Age from DOB
2. Is string contains integer using Regular Expression
3. Auto-Number generation of specific length
4. Totally reverse the string
5. Generate Year and Month
6. Out Parameter

Calculate Age from DOB

C#.Net Code

static int CalculateAge(DateTime BirthDate)
{
    int YearsPassed = DateTime.Now.Year - BirthDate.Year;
    
    if (DateTime.Now.Month < BirthDate.Month || (DateTime.Now.Month == BirthDate.Month && DateTime.Now.Day < BirthDate.Day))
    {
        YearsPassed--;
    }

    return YearsPassed;
}

VB.NET Code

Private Shared Function CalculateAge(BirthDate As DateTime) As Integer
 Dim YearsPassed As Integer = DateTime.Now.Year - BirthDate.Year

 If DateTime.Now.Month < BirthDate.Month OrElse (DateTime.Now.Month = BirthDate.Month AndAlso DateTime.Now.Day < BirthDate.Day) Then
  YearsPassed -= 1
 End If

 Return YearsPassed
End Function

Is string contains integer using Regular Expression

C#.Net Code

string value = "abc123";
bool testValue = Regex.IsMatch(value, @"\d");

if (testValue)
{
    Console.WriteLine("Passed");
}
else
{
    Console.WriteLine("Failed");
}

VB.NET Code

Dim value As String = "abc123"
Dim testValue As Boolean = Regex.IsMatch(value, "\d")

If testValue Then
 Console.WriteLine("Passed")
Else
 Console.WriteLine("Failed")
End If

Auto-Number generation of specific length

C#.Net Code

string uniqueId = "000000";
int newNumber = Convert.ToInt32(uniqueId) + 1;
uniqueId = newNumber.ToString("000000");
Console.WriteLine(uniqueId);

VB.NET Code

Dim uniqueId As String = "000000"
Dim newNumber As Integer = Convert.ToInt32(uniqueId) + 1
uniqueId = newNumber.ToString("000000")
Console.WriteLine(uniqueId)

Totally reverse the string

C#.Net Code

var input = "hello world";
string output = "";

for (int i = input.Length - 1; i >= 0; i--)
{
    output += input[i];
}

Console.WriteLine(output);

VB.NET Code

Dim input = "hello world"
Dim output As String = ""

For i As Integer = input.Length - 1 To 0 Step -1
 output += input(i)
Next

Console.WriteLine(output)

Generate Year and Month

C#.Net Code

for (int i = DateTime.Now.Year; i >= 1990; i--)
{
    Console.WriteLine(i);
}

for (int i = 1; i <= 12; i++)
{
    Console.WriteLine(Convert.ToDateTime(i + "/1/2012").ToString("MMMM"));
}

VB.NET Code

For i As Integer = DateTime.Now.Year To 1990 Step -1
 Console.WriteLine(i)
Next

For i As Integer = 1 To 12
 Console.WriteLine(Convert.ToDateTime(i + "/1/2012").ToString("MMMM"))
Next

Out Parameter

C#.Net Code

var seq = new List<string> { "1", "Blah", "3" };
int temp = 0;
var nums =
    from item in seq
    let success = int.TryParse(item, out temp)
    orderby item
    select success ? temp : 0;
foreach (var num in nums)
{
    Console.WriteLine(num);
}

VB.NET Code

Dim seq = New List(Of String)() With { _
 "1", _
 "Blah", _
 "3" _
}
Dim temp As Integer = 0
Dim nums = _
 Let success = Integer.TryParse(item, temp) _
 Order By item
For Each num As var In nums
 Console.WriteLine(num)
Next