How to get string array item value using foreach loop?

Question

Here is the code:

string[] wordsX ={"word1", "word2","word3"}

with foreach loop want to get the item value and pass to a label

foreach (string w in wordsX)

            {

                Label1.Text = w[1].ToString();
                Label2.Text = w[2].ToString();

            }

It gives an error: Index was outside the bounds of the array.

What exactly do you mean by "item value"? If you mean the word, then `w` _is_ the value. — 41686d6564 stands w. Palestine, Nov 16 '22 at 23:23
Also, what UI framework are you using? WinForms? WebForms? WPF? ...? ASP.NET MVC doesn't seem to be related here. — 41686d6564 stands w. Palestine, Nov 16 '22 at 23:25
I am using ASP.NET, I want this output: word1 word2 for each label text... — user20465780, Nov 16 '22 at 23:27
You mean ASP.NET WebForms? Anyway, you can achieve this using a number of ways. One would be to create an array of the labels: `Label[] labels = new[] { Label1, Label2, Label3 };`. Then, using a `for` loop, you can write something like `for (int i = 0; i < wordsX.Length; i++) { labels[i].Text = wordsX[i]; }`. You'd have to make sure that both arrays have the same length though, or switch to a dictionary or a list of tuples. — 41686d6564 stands w. Palestine, Nov 16 '22 at 23:31
This is essentially a duplicate of [How can i write the text of my String array into multiple Textboxes](https://stackoverflow.com/q/71514198/8967612) — 41686d6564 stands w. Palestine, Nov 16 '22 at 23:33
I am using ASP.NET webforms and using real labels not label arrays... — user20465780, Nov 17 '22 at 00:03
`w[1]` is the second character (index is 0-based) of word `w` — Hans Keﬆing, Nov 17 '22 at 18:08

Jeroen van Langen · Answer 1 · 2022-11-16T23:36:14.903

The problem you are facing is that you want to set the value of the label with a value of an element of wordX

Before you write some extra if statement and switches. You could use clever some linq. The trick is, create an array of those labels and you can zip them

Something like this:

public static void Main()
{
    // the words
    string[] wordsX ={"word1", "word2","word3"};
    // the labels as array
    Label[] labels = {Label1, Label2};
    
    // zip them together into a new anonymous class
    // (use the shortest collection)
    var combined = wordsX.Zip(labels, (w, l) => new { Word = w, Label = l});
    
    // display them with foreach.
    foreach (var item in combined)
    {
        // assign the label.Text to the word
        item.Label.Text = item.Word;
    }
}

Breakdown:

               // first collection
var combined = wordsX                
                   // second collection
                   .Zip(labels,      
                       // function to return new instance (class with no name)
                       (w, l) => new { Word = w, Label = l});

the problem is that I need to pass the array items in real Label.text in ASP.NET how to do that? i am doing this in ASP.NET Webforms — user20465780, Nov 16 '22 at 23:55
It also works with real labels: `Label[] labels = {Label1, Label2};` — Jeroen van Langen, Nov 17 '22 at 09:54

score 0 · Answer 2 · answered Nov 17 '22 at 17:56

You need to access you labels by runtime string instead of compile-time symbol. For that you can use Controls.Find.

string[] wordsX ={"word1", "word2","word3"};
for (int i=0; i< wordsX.Length; i++)
{
    var controlId = string.Format("Label{0}", i);
    var control = this.Control.Find(controlId).OfType<Label>().FirstOrDefault();
    if (control != null) control.Text = wordsX[i];
}

score 0 · Answer 3 · answered Nov 17 '22 at 19:32

Like all problems, we don't know if there are just 3 values, or say 1` to 15 values (labels on the page).

WORSE is WHY use a loop and HAVING to type in the label names - even into a array? (Defeats the WHOLE purpose of using a loop!).

So, lets assume a list, say 1 to 10 items, and thus:

 Lable1
 Lable2
 ... to 10, or 20, or 5 or 50!!!!

Ok, so not only do we need to deal with passing a list of say only 5 values, WE ALSO STILL have to blank out the ones that don't have a value (or did anyone here think of that????)

So, you can do it this way:

        List<string> Mylist = new List<string> { "one", "Two", "Three", "Four" };

        for (int i = 1; i <= 10; i++)
        {
            Label MyLabel = Page.FindControl("Label" + i) as Label;
            if (i <= Mylist.Count)
                MyLabel.Text = Mylist[i-1];
            else
                MyLabel.Text = "";
        }

Above assumes we have Label1 to label10, but it would work for 5 or 50 or whatever how many you have.

How to get string array item value using foreach loop?

3 Answers3