c# remove strings from an array

Question

How can i remove any strings from an array and have only integers instead

string[] result = col["uncheckedFoods"].Split(',');

I have

[0] = on;      // remove this string
[1] = 22;
[2] = 23;
[3] = off;      // remove this string
[4] = 24;

I want

[0] = 22;
[1] = 23;
[2] = 24;

I tried

var commaSepratedID = string.Join(",", result);

var data = Regex.Replace(commaSepratedID, "[^,0-9]+", string.Empty);

But there is a comma before first element, is there any better way to remove strings ?

score 12 · Accepted Answer · answered Nov 16 '16 at 09:37

12

This selects all strings which can be parsed as int

string[] result = new string[5];
result[0] = "on";      // remove this string
result[1] = "22";
result[2] = "23";
result[3] = "off";      // remove this string
result[4] = "24";
int temp;
result = result.Where(x => int.TryParse(x, out temp)).ToArray();

answered Nov 16 '16 at 09:37

fubo

44,811
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I don't know much about this so is this better than regex method in terms of efficiency? – Sean83 Nov 16 '16 at 09:46
Thank you, works fine , SO system is designed to wait 5 minutes to accept your answer. – Shaiju T Nov 16 '16 at 09:48
@Sean83 in this case it should be faster compared to RegEx – fubo Nov 16 '16 at 09:52

score 0 · Answer 2 · answered Nov 16 '16 at 09:44

0

To also support double I would do something like this:

public static bool IsNumeric(string input, NumberStyles numberStyle)
{
   double temp;
   return Double.TryParse(input, numberStyle, CultureInfo.CurrentCulture, out temp);
}

and then

string[] result = new string[] {"abc", "10", "4.1" };
var res = result.Where(b => IsNumeric(b, NumberStyles.Number));
// res contains "10" and "4.1"

answered Nov 16 '16 at 09:44

Bidou

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9
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I only need integers from an array, this answers might help someone in future. Thank you. – Shaiju T Nov 16 '16 at 09:50

score 0 · Answer 3 · edited Nov 16 '16 at 10:21

0

Try this

  dynamic[] result = { "23", "RT", "43", "67", "gf", "43" };

                for(int i=1;i<=result.Count();i++)
                {
                    var getvalue = result[i];
                    int num;
                    if (int.TryParse(getvalue, out num))
                    {
                        Console.Write(num);
                        Console.ReadLine();
                        // It's a number!
                    }
                }

edited Nov 16 '16 at 10:21

Bharat

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answered Nov 16 '16 at 10:15

AmanMiddha

31
1
9

1

why a dynamic type? what is the benefit of your answer over the accepted one? – Bidou Nov 16 '16 at 10:33
dynamic use when values data type are not clean but in this case if we use String array then result will be same – AmanMiddha Nov 16 '16 at 10:40
Never use `dynamic` if not needed. In this case, you have to use `string` (even if it is working with dynamic...) – Bidou Nov 16 '16 at 10:42
ok thanks, but when i have no idea which type of data will come dynamically in arrray then what should i do? – AmanMiddha Nov 16 '16 at 10:45
if you have any idea or example related to this , then it will be very helpful for me – AmanMiddha Nov 16 '16 at 10:46

c# remove strings from an array

3 Answers3