[c#] How to determine if string contains specific substring within the first X characters

I want to check whether Value1 below contains "abc" within the first X characters. How would you check this with an if statement?

var Value1 = "ddabcgghh";

if (Value1.Contains("abc"))
{
    found = true;
}

It could be within the first 3, 4 or 5 characters.

if (Value1.StartsWith("abc")) { found = true; }

You can also use regular expressions (less readable though)

string regex = "^.{0,7}abc";

System.Text.RegularExpressions.Regex reg = new System.Text.RegularExpressions.Regex(regex);
string Value1 = "sssddabcgghh";

Console.WriteLine(reg.Match(Value1).Success);

You're close... but use: if (Value1.StartsWith("abc"))

A more explicit version is

found = Value1.StartsWith("abc", StringComparison.Ordinal);

It's best to always explicitly list the particular comparison you are doing. The String class can be somewhat inconsistent with the type of comparisons that are used.

Adding on from the answer below i have created this method:

    public static bool ContainsInvalidStrings(IList<string> invalidStrings,string stringToCheck)
    {

        foreach (string invalidString in invalidStrings)
        {
            var index = stringToCheck.IndexOf(invalidString, StringComparison.InvariantCultureIgnoreCase);
            if (index != -1)
            {
                return true;
            }
        }
        return false;
    }

it can be used like this:

            var unsupportedTypes = new List<string>()
        {
            "POINT Empty",
            "MULTIPOINT",
            "MULTILINESTRING",
            "MULTIPOLYGON",
            "GEOMETRYCOLLECTION",
            "CIRCULARSTRING",
            "COMPOUNDCURVE",
            "CURVEPOLYGON",
            "MULTICURVE",
            "TRIANGLE",
            "TIN",
            "POLYHEDRALSURFACE"
        };


            bool hasInvalidValues =   ContainsInvalidStrings(unsupportedTypes,possibleWKT);

you can check for multiple invalid values this way.

You can also use regular expressions (less readable though)

string regex = "^.{0,7}abc";

System.Text.RegularExpressions.Regex reg = new System.Text.RegularExpressions.Regex(regex);
string Value1 = "sssddabcgghh";

Console.WriteLine(reg.Match(Value1).Success);

A more explicit version is

found = Value1.StartsWith("abc", StringComparison.Ordinal);

It's best to always explicitly list the particular comparison you are doing. The String class can be somewhat inconsistent with the type of comparisons that are used.

I would use one of the of the overloads of the IndexOf method

bool found = Value1.IndexOf("abc", 0, 7) != -1;

if (Value1.StartsWith("abc")) { found = true; }

shorter version:

found = Value1.StartsWith("abc");

sorry, but I am a stickler for 'less' code.

Given the edit of the questioner I would actually go with something that accepted an offset, this may in fact be a Great place to an Extension method that overloads StartsWith

public static class StackOverflowExtensions
{
    public static bool StartsWith(this String val, string findString, int count)
    {
        return val.Substring(0, count).Contains(findString);
    }
}

Or if you need to set the value of found:

found = Value1.StartsWith("abc")

Edit: Given your edit, I would do something like:

found = Value1.Substring(0, 5).Contains("abc")

You're close... but use: if (Value1.StartsWith("abc"))

You can also use regular expressions (less readable though)

string regex = "^.{0,7}abc";

System.Text.RegularExpressions.Regex reg = new System.Text.RegularExpressions.Regex(regex);
string Value1 = "sssddabcgghh";

Console.WriteLine(reg.Match(Value1).Success);

shorter version:

found = Value1.StartsWith("abc");

sorry, but I am a stickler for 'less' code.

Given the edit of the questioner I would actually go with something that accepted an offset, this may in fact be a Great place to an Extension method that overloads StartsWith

public static class StackOverflowExtensions
{
    public static bool StartsWith(this String val, string findString, int count)
    {
        return val.Substring(0, count).Contains(findString);
    }
}

Use IndexOf is easier and high performance.

int index = Value1.IndexOf("abc");
bool found = index >= 0 && index < x;

A more explicit version is

found = Value1.StartsWith("abc", StringComparison.Ordinal);

It's best to always explicitly list the particular comparison you are doing. The String class can be somewhat inconsistent with the type of comparisons that are used.

Adding on from the answer below i have created this method:

    public static bool ContainsInvalidStrings(IList<string> invalidStrings,string stringToCheck)
    {

        foreach (string invalidString in invalidStrings)
        {
            var index = stringToCheck.IndexOf(invalidString, StringComparison.InvariantCultureIgnoreCase);
            if (index != -1)
            {
                return true;
            }
        }
        return false;
    }

it can be used like this:

            var unsupportedTypes = new List<string>()
        {
            "POINT Empty",
            "MULTIPOINT",
            "MULTILINESTRING",
            "MULTIPOLYGON",
            "GEOMETRYCOLLECTION",
            "CIRCULARSTRING",
            "COMPOUNDCURVE",
            "CURVEPOLYGON",
            "MULTICURVE",
            "TRIANGLE",
            "TIN",
            "POLYHEDRALSURFACE"
        };


            bool hasInvalidValues =   ContainsInvalidStrings(unsupportedTypes,possibleWKT);

you can check for multiple invalid values this way.

Use IndexOf is easier and high performance.

int index = Value1.IndexOf("abc");
bool found = index >= 0 && index < x;

This is what you need :

if (Value1.StartsWith("abc"))
{
found = true;
}

Or if you need to set the value of found:

found = Value1.StartsWith("abc")

Edit: Given your edit, I would do something like:

found = Value1.Substring(0, 5).Contains("abc")

Use IndexOf is easier and high performance.

int index = Value1.IndexOf("abc");
bool found = index >= 0 && index < x;

You're close... but use: if (Value1.StartsWith("abc"))

This is what you need :

if (Value1.StartsWith("abc"))
{
found = true;
}

Or if you need to set the value of found:

found = Value1.StartsWith("abc")

Edit: Given your edit, I would do something like:

found = Value1.Substring(0, 5).Contains("abc")

I would use one of the of the overloads of the IndexOf method

bool found = Value1.IndexOf("abc", 0, 7) != -1;

You're close... but use: if (Value1.StartsWith("abc"))

shorter version:

found = Value1.StartsWith("abc");

sorry, but I am a stickler for 'less' code.

Given the edit of the questioner I would actually go with something that accepted an offset, this may in fact be a Great place to an Extension method that overloads StartsWith

public static class StackOverflowExtensions
{
    public static bool StartsWith(this String val, string findString, int count)
    {
        return val.Substring(0, count).Contains(findString);
    }
}

if (Value1.StartsWith("abc")) { found = true; }

This is what you need :

if (Value1.StartsWith("abc"))
{
found = true;
}

Or if you need to set the value of found:

found = Value1.StartsWith("abc")

Edit: Given your edit, I would do something like:

found = Value1.Substring(0, 5).Contains("abc")

This is what you need :

if (Value1.StartsWith("abc"))
{
found = true;
}

if (Value1.StartsWith("abc")) { found = true; }

You can also use regular expressions (less readable though)

string regex = "^.{0,7}abc";

System.Text.RegularExpressions.Regex reg = new System.Text.RegularExpressions.Regex(regex);
string Value1 = "sssddabcgghh";

Console.WriteLine(reg.Match(Value1).Success);