Contains Unicode Character checking fail

Question

    public bool ContainsUnicodeCharacter(char[] input)
    {
        const int MaxAnsiCode = 255;
        bool temp;
        string s;

        foreach (char a in input)
        {
            s = a.ToString();
            temp = s.Any(c => c > MaxAnsiCode);

            if (temp == false)
            {
                return false;
            }
        }            
    }

This code used to check unicode exist or not on input char array.

I got error message : " ContainsUnicodeCharacter(char[])': not all code paths return a value"

What went wrong here, Please help. Thank You.

Well, `s = a.ToString(); temp = s.Any(c => c > MaxAnsiCode);` can be just replaced with `temp = a > MaxAnsiCode;`. — Vlad, May 30 '13 at 15:27

usr · Answer 1 · 2013-05-30T15:32:16.143

5

Your method is not well thought through. It can be done much simpler:

public static bool ContainsUnicodeCharacter(this IEnumerable<char> input)
{
    const int MaxAnsiCode = 255;
    return input.Any(c => c > MaxAnsiCode);
}

You had two nested loops there without reason.

I made the method a generally applicable extension method.

edited May 30 '13 at 15:32

answered May 30 '13 at 15:22

usr

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2

If you made the parameter `input` have type `IEnumerable`, the method could easily be called with a string or any collection of `char` values. Also, that signature will signal to the callers: "We won't change your `input`, we'll just loop through it." – Jeppe Stig Nielsen May 30 '13 at 15:30
This is another solution without using lambda expresions http://stackoverflow.com/a/40252987/348551 – Yiannis Mpourkelis Oct 27 '16 at 10:22

score 3 · Answer 2 · answered May 30 '13 at 15:19

You need to add return true; just before the last }, but I also think you have the test reversed:

public bool ContainsUnicodeCharacter(char[] input)
{
    const int MaxAnsiCode = 255;
    bool temp;
    string s;

    foreach (char a in input)
    {
        s = a.ToString();
        temp = s.Any(c => c > MaxAnsiCode); // true if unicode found

        if (temp == true)
        {
            return true;
        }
    }

    return false;
}

score 3 · Answer 3 · answered May 30 '13 at 15:23

Further to @egrunin's answer, I don't know why you loop through all of the characters and then cast them to a string, just so you can use a Linq method on the resulting character arrayt. You could simplify your entire method (maintaining the same logic) like this:

public bool ContainsUnicodeCharacter(char[] input)
{
    const int MaxAnsiCode = 255;

    return input.Any(c => c > MaxAnsiCode);
}

score 0 · Answer 4 · answered May 30 '13 at 15:23

You only have 1 return statement which is part if a conditional if...as mentioned you can add return true; but the reason you got that error is that your function had nothing to return if temp never equated to false

public bool ContainsUnicodeCharacter(char[] input)
    {
        const int MaxAnsiCode = 255;
        bool temp;
        string s;

        foreach (char a in input)
        {
            s = a.ToString();
            temp = s.Any(c => c > MaxAnsiCode);
            if (temp == false)
            {
               return false;
             }
        } 
         return true;  
    }

Contains Unicode Character checking fail

4 Answers4