All with Contains on lower case

Pangram
Pangram in C# 
using System.Linq;

public static class Pangram
{
    private const string Letters = "abcdefghijklmnopqrstuvwxyz";
    
    public static bool IsPangram(string input)
    {
        var lowerCaseInput = input.ToLower();
        return Letters.All(letter => lowerCaseInput.Contains(letter));
    }
}
  • This begins by lowercasing the input by using ToLower.
  • It then checks if all letters in the alphabet are contained in the input, using the LINQ method All with the String method Contains.

Instead of lowercasing the input, Contains could take an optional StringComparison argument, but a case-insensitive comparison is about seven times slower than lowercasing the input and then doing an exact comparison.

6th Nov 2024 · Found it useful?

Other Approaches to Pangram in C#

Other ways our community solved this exercise
private static readonly StringComparison xcase = StringComparison.CurrentCultureIgnoreCase;

public static bool IsPangram(string input) =>
    "abcdefghijklmnopqrstuvwxyz".All(c => input.Contains(c, xcase));
All with Contains using case insensitve

Use All with Contains using case insensitive. 

// a - z
if (letter > 96 && letter < 123)
    phrasemask |= 1 << (letter - 'a');
// A - Z
else if (letter > 64 && letter < 91)
    phrasemask |= 1 << (letter - 'A');
Bit field

Use a bit field to keep track of used letters.