switch case problem with object variable

Question

1.00/5 (2 votes)

See more:

Hi I have a problem with this code im converting from vb to c# and when while im converting i found this error can any one help me :

here is my method i declared here the KEY as an object and i want to use the switch case but it gives me that error that i should declare only int or bool or string but not object : "A switch expression or case label must be a bool, char, string, integral, enum, or corresponding nullable type"
i still new for converting code from vb to c# i need a small help

C#

static private bool validateSiteAddressDetails(string sCountry, long sNr, string sNrAlf, long sPC, string sPhone, string sEmail, string sFax, string sStreet, string sCity, Hashtable ht_AddressDetails)
{

    long rv = 0;
    rv = 0;
object key = null;


    foreach (object key_loopVariable in ht_AddressDetails.Keys) {
        key = key_loopVariable;
        switch ( key) {
            case "city_text":
                if (sCity != ht_AddressDetails(key).ToString()) {
                    rv = -1;
                    key= 215;
                }
                break;
            case "street_text":
                if (sStreet != ht_AddressDetails(key).ToString()) {
                    rv = -1;
                    key= 215;
                }

                break;
            case "house_nr":
                if (sNr != Convert.ToInt32(ht_AddressDetails(key).ToString())) {
                    rv = -1;
                    key= 215;
                }
                break;
            case "house_alf":
                if (sNrAlf != ht_AddressDetails(key).ToString()) {
                    rv = -1;
                    key= 215;
                }
                break;
            case "contact_phone":
                if (sPhone != ht_AddressDetails(key).ToString()) {
                    rv = -1;
                    key = 215;
                }
                break;
            case "contact_email":
                if (sEmail != ht_AddressDetails(key).ToString()) {
                    rv = -1;
                    key = 215;
                }
                break;
            case "contact_fax":
                if (sFax != ht_AddressDetails(key).ToString()) {
                    rv = -1;
                    key = 215;
                }
                break;
            case "country":
                if (sCountry != ht_AddressDetails(key).ToString()) {
                    rv = -1;
                    key =  215;
                }
                break;
            case "postal_code":
                if (sPC != Convert.ToInt32(ht_AddressDetails(key).ToString())) {
                    rv = -1;
                    key = 215;
                }
                break;
        }

    }
    key = 215;


    return Convert.ToBoolean(rv);

}

and this is y vb code:

VB

<pre lang="xml">Private Function validateSiteAddressDetails(ByVal sCountry As String, _
                                       ByVal sNr As Long, ByVal sNrAlf As String, ByVal sPC As Long, _
                                       ByVal sPhone As String, ByVal sEmail As String, ByVal sFax As String, ByVal sStreet As String, ByVal sCity As String, _
                                       ByVal ht_AddressDetails As Hashtable) As Boolean

        Dim rv As Long
        rv = 0
        Dim key As Object

        For Each key In ht_AddressDetails.Keys

            Select Case key
                Case "city_text"
                    If sCity <> ht_AddressDetails(key).ToString() Then
                        rv = -1
                        GoTo 215
                    End If
                Case "street_text"
                    If sStreet <> ht_AddressDetails(key).ToString() Then
                        rv = -1
                        GoTo 215
                    End If

                Case "house_nr"
                    If sNr <> Convert.ToInt32(ht_AddressDetails(key).ToString()) Then
                        rv = -1
                        GoTo 215
                    End If
                Case "house_alf"
                    If sNrAlf <> ht_AddressDetails(key).ToString() Then
                        rv = -1
                        GoTo 215
                    End If
                Case "contact_phone"
                    If sPhone <> ht_AddressDetails(key).ToString() Then
                        rv = -1
                        GoTo 215
                    End If
                Case "contact_email"
                    If sEmail <> ht_AddressDetails(key).ToString() Then
                        rv = -1
                        GoTo 215
                    End If
                Case "contact_fax"
                    If sFax <> ht_AddressDetails(key).ToString() Then
                        rv = -1
                        GoTo 215
                    End If
                Case "country"
                    If sCountry <> ht_AddressDetails(key).ToString() Then
                        rv = -1
                        GoTo 215
                    End If
                Case "postal_code"
                    If sPC <> Convert.ToInt32(ht_AddressDetails(key).ToString()) Then
                        rv = -1
                        GoTo 215
                    End If
            End Select

        Next


215:
        Return rv

    End Function

Posted 19-Jan-15 19:10pm

Hesham el Masry

Updated 19-Jan-15 19:39pm

v2

Add a Solution

Comments

Sergey Alexandrovich Kryukov 20-Jan-15 1:15am

It's too wrong from the very beginning to discuss any bugs. Stop hard-coding, start programming. First of all, get rid of all the immediate string constants, stop repeating any code, such as this assignment of -1 and 215; this is totally non-maintainable...
—SA

Hesham el Masry 20-Jan-15 1:34am

Thank you so much , but how i do it without switch case or what iam still a beginner just asking for small help

Sergey Alexandrovich Kryukov 20-Jan-15 2:19am

I did not say "without switch case", I meant all those constants. But long case is also bad. It's all about desing of reasonable code. At least define some enumeration instead of constants.
—SA

Tejas Vaishnav 20-Jan-15 1:30am

can you please also add you vb code too, so we can help you. just use improve question functionality to edit you question, and add you vb code for same.

Hesham el Masry 20-Jan-15 1:39am

thank you Tejas i updated my vb code you can check it now

Tejas Vaishnav 20-Jan-15 5:26am

Please check my answer..., and if it will help you to solve your problem, please don't forget to accept it as your answer and also rate it.

Tejas Vaishnav 21-Jan-15 1:08am

Is your problem solved? have you check my answer?

3 solutions

Solution 1

OK. In order:
First: Why have the switch at all? Have separate validating function for each field. Alternatively, have series of elseifs (since you already have ifs within switch case.

Second: GoTos went out of style in the 90s last century.

Third: You use .ToString in ht_AddresssDetails(key) - obviously you know about the method. Why not use it on the key? And why not have key as String? You could also try for each key as string from ... it will call .ToString on the object for you.

If this helps please take time to accept the solution.

Posted 19-Jan-15 20:18pm

Sinisa Hajnal

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Tejas Vaishnav · Accepted Answer · 2015-01-19T23:19:00

Actually you are accessing value from your has-table, so you need to first of check how you has-table has been created, as has-table is accepting all the things like 'Key' and 'Value' as object data type, that means you can add combination of value like key is type of integer and value is string, for key is type of string and value is integer, you can create your own combination with any primitive data type as well as user define data type too.

so while converting your code from vb to c#, you need to make some changes manually as here in your code needs.

so please check your ht_AddressDetails has table, if it will having key of string data type then use your 'key' variable declared as string instead of object type.

and make appropriate changes to your code like this...

C#

string key = string.Empty;
bool rv = true;


foreach (string key_loopVariable in ht_AddressDetails.Keys) {
key = key_loopVariable;
    switch ( key) {
        case "city_text":
            if (sCity != Convert.ToString(ht_AddressDetails[key])) {
                rv = false;
            }
            break;
    }
//your other validation goes here
    if(!rv)
      break;
}

I have just given example, you need to modify your code by your own way as per you requirement.

BillWoodruff · Accepted Answer · 2015-01-20T01:16:00

Take a look at this example:

C#

Hashtable ht = new Hashtable();

private void TestHashTable()
{
    ht.Add("what", 12);
    ht.Add("how", 14);
    
    foreach (var key in ht.Keys)
    {
        switch (key.ToString())
        {
            case "what"
                Console.WriteLine("it's a what");
                break;
            case "how":
                Console.WriteLine("it's a how");
                break;
        }
    }
}

A HashTable's Keys are an ICollection of Objects; in the case you used Type String for all the Keys, then 'ToString() will case the Key Object back to its original String Type where it can be used as the selector for a Switch/Case statement as shown above.

If you had used a Dictionary<string, int> for your Data Structure, you could use the Key directly without casting using 'ToString.

A HashTable lets you "get away with" adding Key-Value pairs where the Keys are different Type Objects; a Dictionary is strongly typed and all Keys must be of the same Type.

switch case problem with object variable

3 solutions

Solution 1

Solution 3

Solution 4

Add your solution here

Preview 0