for loop in vb.net add a counter to existing string

Question

i hae a for loop which goes like this -

for i = 0 as integer to 100
    result &= "Name" & sqldr("name")
    result &= "Lastname" & sqldr("lastname")
    result &= "dob" & sqldr("dob")
next

the sqldr is the sql datareader (not important here) i want my end result to be

Name1 = Sam
Lastname1 = Davis
dob1 = 01/01/1966

Name2 = 
...
Name3 = 

and so on depending on how manyrecords are in database. how do i make this happen in this for loop?

Answer 1

This will do it:

for i = 0 as integer to 100
    result &= "ApplicantName" & i.ToString() & " = " & sqldr("name")
    result &= "Lastname" & i.ToString() & " = " sqldr("lastname")
    result &= "dob" & i.ToString() & " = " sqldr("dob") & "\n\n"
next

But, for better performance, you should be using string.Format and StringBuilder:

Dim sb as StringBuilder = new StringBuilder()
for i = 0 as Integer to 100
    sb.Append(String.Format("ApplicantName{0} = {1}", i, sqldr("name"))
    sb.Append(String.Format("Lastname{0} = {1}", i, sqldr("lastname"))
    sb.Append(String.Format("dob{0} = {1}\n\n", i, sqldr("dob"))
next
Dim result as String = sb.ToString()

StringBuilder also has an AppendFormat overload, that makes this even easier:

Dim sb as StringBuilder = new StringBuilder()
for i = 0 as Integer to 100
    sb.AppendFormat("ApplicantName{0} = {1}", i, sqldr("name")
    sb.AppendFormat("Lastname{0} = {1}", i, sqldr("lastname")
    sb.AppendFormat("dob{0} = {1}\n\n", i, sqldr("dob")
next
Dim result as String = sb.ToString()

Answer 2

Well, first of all you should be using a StringBuilder as it is more efficient than concatenating strings.

So the following should yield the expected result (sorry I am or aquainted to C#):

Dim sb as StringBuilder = new StringBuilder() ' that is where I am not so sure

for i = 0 as integer to 100
    sb.AppendFormat("Name{0} = {1}", i, sqldr("name")
    sb.AppendFormat("Lastname{0} = {1}", i, sqldr("lastname")
    sb.AppendFormat("dob{0} = {1}", i, sqldr("dob")
next

result = sb.ToString()

Answer 3

you'll need to do a select before your For loop. The select will get the total number of records returned. Store that number in a variable.

Dim sqlcount as integer = 100 'this should actually be the result of your sql query
for i = 0 as integer to sqlcount
    result &= "Name" & sqldr("name")
    result &= "Lastname" & sqldr("lastname")
    result &= "dob" & sqldr("dob")
    i = i + 1
next