CODEWITHSUNDEEP
c#
Lemons
Lemons

Reputation: 176

printing items in a list with a for loop

I want to build tab-delimited string of shopping cart content. I cycle through a list using a for loop so that items in the cart are meant to be outputted however, only the last item in that list is outputted.

public string Display()
{
    CartClass CartList = CartClass.GetCart();
    String display = "" ;

    for (int i = 0; i < CartList.CartList.Count(); i++)
    {
        Movies Movie = CartList.CartList[i];
        display = String.Format(i + 1 + "." + "\t" + 
           Movie.MovieName + "\t" + "£" + Movie.MovieCost.ToString());
    }
    return display;
}

how can I solve this?

Side note: ultimately I'll use it to display on web page, but at this point I want to understand why it does not return text for all items.

Upvotes: 0

Views: 912

Answers (9)

Omri Aharon
Omri Aharon

Reputation: 17064

You only see the last because you're doing assignment in each loop iteration. You need to do += instead of =.

public string Display()
{
    CartClass CartList = CartClass.GetCart();
    String display = "" ;

    for (int i = 0; i < CartList.CartList.Count(); i++)
    {
        Movies Movie = CartList.CartList[i];
        display += String.Format(i + 1 + "." + "\t" + 
            Movie.MovieName + "\t" + "£" + Movie.MovieCost.ToString()) + "\n";
    }
    return display;
}

Note that it is generally better to use StringBuilder for building large strings.

Upvotes: 12

Sudhakar Tillapudi
Sudhakar Tillapudi

Reputation: 26219

As already other answers pointed out that you need to append the String using Concatnation operator +,I Would like to suggest you to use StringBuilder.

StringBuilder sb = new StringBuilder();
for (int i = 0; i < CartList.CartList.Count(); i++)
    {
        Movies Movie = CartList.CartList[i];
        sb .Append(String.Format(i + 1 + "." + "\t" + Movie.MovieName + "\t" + "£" + Movie.MovieCost.ToString());
    }
    return sb.ToString();

Upvotes: 3

D Stanley
D Stanley

Reputation: 152644

You are overwriting display in each loop.

The simplest change is to change = to += :

    //      V-----
    display += String.Format(i + 1 + "." + "\t" + Movie.MovieName + "\t" + "£" + Movie.MovieCost.ToString());

But you may find StringBuilder more performant if you have a LOT of strings.

Upvotes: 2

Matas Vaitkevicius
Matas Vaitkevicius

Reputation: 61529

I think you want this.

public string Display()
{
CartClass CartList = CartClass.GetCart();
String display = "" ;

for (int i = 0; i < CartList.CartList.Count(); i++)
{
    Movies Movie = CartList.CartList[i];
    display += String.Format(i + 1 + "." + "\t" + Movie.MovieName + "\t" + "£" + Movie.MovieCost.ToString());
}
return display;
}

Upvotes: 1

JSK NS
JSK NS

Reputation: 3446

You need to concatenate each entry to display as follows (notice +=):

public string Display()
{
    CartClass CartList = CartClass.GetCart();
    String display = "" ;

    for (int i = 0; i < CartList.CartList.Count(); i++)
    {
        Movies Movie = CartList.CartList[i];
        display += String.Format(i + 1 + "." + "\t" + Movie.MovieName + "\t" + "£" + Movie.MovieCost.ToString());

    }
    return display;
}

Upvotes: 2

Amit Joki
Amit Joki

Reputation: 59292

You are overriding the display variable. Try to concat +=

Upvotes: 2

Bearcat9425
Bearcat9425

Reputation: 1608

You are using = sign to set Display text you need to use += or the string builder class.

Upvotes: 3

Brad Faircloth
Brad Faircloth

Reputation: 327

You are replacing the value of your variable with the next item in the loop... try adding it.

display += String.Format(i + 1 + "." + "\t" + Movie.MovieName + "\t" + "£" + Movie.MovieCost.ToString());

Upvotes: 2

T McKeown
T McKeown

Reputation: 12857

You really should be using a StringBuilder here:

System.Text.StringBuilder sb = new StringBuilder();
for (int i = 0; i < CartList.CartList.Count(); i++)
{
    Movies Movie = CartList.CartList[i];
    sb.Append( String.Format(i + 1 + "." + "\t" + Movie.MovieName + "\t" + "£" + Movie.MovieCost.ToString()));
}
return sb.ToString();

Upvotes: 7

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