How to determine if string contains specific substring ignoring the case sensitive

Question

I want to check whether string below contains top/ TOP/toP/ Top/TOp/ Top in c#. My code is like

string str = null;
        str = "CSharp Top11111 10 BOOKS";
        if (str.Contains("top") == true)
        {
            Console.WriteLine("The string Contains() 'TOP' ");
        }
        else
        {
            Console.WriteLine("The String does not Contains() 'TOP'");
        }

But it return true only when my string contain 'top'. How can return true for all other scenarios too? I know this may be simple, but I searched a Lot didn't find any solutions

score 8 · Accepted Answer · answered Apr 28 '16 at 06:07

8

Without the need for any conversion:

bool found = "My Name is".IndexOf("name", StringComparison.OrdinalIgnoreCase) >= 0;

answered Apr 28 '16 at 06:07

Zein Makki

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score 4 · Answer 2 · answered Apr 28 '16 at 06:02

Use one of both: .ToLower() or .ToUpper

string str = null;
    str = "CSharp Top11111 10 BOOKS";
    if (str.ToLower().Contains("top") == true)
    {
        Console.WriteLine("The string Contains() 'TOP' ");
    }
    else
    {
        Console.WriteLine("The String does not Contains() 'TOP'");
    }

How to determine if string contains specific substring ignoring the case sensitive

2 Answers2