How to retrieve value from a textbox when using Contains or IndexOf methods to check the status or index of values?

Question

I just try to check if an array contains a particular value or what is index of it not by showing respective values in brackets but typing them on textbox. How to go about that?

private void button3_Click(object sender, EventArgs e)
{
    int[] values = new int[6];
    values[0] = 2;
    values[1] = 9;
    values[2] = 5;
    values[3] = 15;
    values[4] = 8;
    values[5] = 25
    bool status = values.Contains(?);//I want to retrieve it from txtbox  
    label1.Text = $"{status}";
    int indexi = Array.IndexOf(values,?); //same is true for this method aswell.         
    label2.Text = $"{indexi}";


    foreach (int item in values)
    {               
        listBox1.Items.Add(item);
    }
}

What is your *specific* issue? Do you see an error message? An `Exception`? — dymanoid, May 04 '18 at 09:19
Is your question how to parse your `Textbox.Text` to `int`? Well, use `int.Parse(Textbox.Text)` or better `int.TryParse(Textbox.Text, out int value)` — Tim Schmelter, May 04 '18 at 09:19
Question is clear I think... How to get value from textbox and check its index or existence in array? — Cavid Hummatov, May 04 '18 at 09:22
The question is not clear because the value of the textbox is of type `string` not `int` and you didn't explain whether you want to convert it to an int or do something else. Did you read Tim's comment? Is that what you're trying to do? — 41686d6564 stands w. Palestine, May 04 '18 at 09:23

score 0 · Answer 1 · answered May 04 '18 at 09:28

0

If you just want to retrieve an int value from a textbox and see if that number exists in the values array:

int position = Array.IndexOf(values, Convert.toInt32(Textbox.Text)); 
if (position > -1) //If it finds the index position it will be greater than -1
{
   bool status = true;
}

This simply retrieves the string value from the textbox, converts it to a integer and will look for it's index in the values array. If "position" variable is greater than -1 that means it found a valid position in the array.

Check this: Checking if a string array contains a value, and if so, getting its position

answered May 04 '18 at 09:28

Lewis Hotchen

11
2

I was doing the same without using : if (array > -1) and I got -1 on the label all the time? what does "-1" refers to in the array? – Cavid Hummatov May 04 '18 at 09:33
@CavidHummatov if it returns -1 that means it could not find the value in the array. – Lewis Hotchen May 04 '18 at 09:47
and what does "status" here indicate? it gives "doesnt exist in the context" error – Cavid Hummatov May 04 '18 at 09:49
I declared my boolean with in the if statement, so it only exists there. If you want to use it elsewhere declare it at a higher scope where you need to use it. – Lewis Hotchen May 04 '18 at 10:02

score 0 · Answer 2 · answered May 04 '18 at 09:34

0

You can do it like this

int[] values = new int[6];
        values[0] = 2;
        values[1] = 9;
        values[2] = 5;
        values[3] = 15;
        values[4] = 8;
        values[5] = 25;
        bool status = values.Contains(Convert.ToInt16(txtValue.Text));//I want to retrieve it from txtbox  
        lblindex.Text = status.ToString();
        int indexi =Array.IndexOf(values,Convert.ToInt16(txtValue.Text)); //same is true for this method aswell.         
        lblindex.Text = indexi.ToString();
        foreach (int item in values)
        {
            listBox1.Items.Add(item);
        }

answered May 04 '18 at 09:34

swapnil kamle

115
1
8

Reply on Your Question:I was doing the same without using : if (array > -1) and I got -1 on the label all the time? what does "-1" refers to in the array? Ans: You are using Int Array, so before passing the textbox value you need to parse the value in to int and pass it to Indexof function. – swapnil kamle May 04 '18 at 09:37
bool status = values.Contains(Convert.ToInt16(txtValue.Text)); lblindex.Text = status.ToString(); - gives format exception error. – Cavid Hummatov May 04 '18 at 10:19
I've just figure out that using them both together throws FormatException error. What was the reason? how to keep both of methods without error? – Cavid Hummatov May 04 '18 at 10:50

How to retrieve value from a textbox when using Contains or IndexOf methods to check the status or index of values?

2 Answers2