C# - NullReferenceException when attempting to parse a string to float in an array

Question

This is blowing my mind right now, I don't know what I'm doing wrong. What I'm attempting to do is grab the contents of a textbox, splitting values separated by a comma, putting them into an array and then parsing them to float and put them into another array. System.NullReferenceException: Object reference not set to an instance of an object.

        Xt = s1.Split(',').Select(s1V => s1V.Trim()).ToArray();
        Yt = s2.Split(',').Select(s2V => s2V.Trim()).ToArray();
        float number;
        if (Xt.Length == Yt.Length)
        {
            int i = 0;
            foreach (var value in Xt)
            {
                // Console.WriteLine("l:"+Xt.Length+" "+Xt[i]+"+");
                if (Xt[i] != null)
                {
                    Xi[i] = float.Parse(Xt[i]);
                }
                //  Yi[i] = float.Parse(Yt[i]);
                i++;
            }
 ...

Well I defined it globally as "float[] Xi;" And no, didn't initialize it, is that what's causing my problem? — Angel Medina, Oct 11 '15 at 23:18
Yes. Assign `Xi = new float[Xt.Length];` before entering the loop. — MarcinJuraszek, Oct 11 '15 at 23:20

score 0 · Answer 1 · answered Oct 11 '15 at 23:25

string s1 = textBox1.Text;
        string s2 = textBox2.Text;            
        float[] Yi;
        Xt = s1.Split(',').Select(s1V => s1V.Trim()).ToArray();
        Yt = s2.Split(',').Select(s2V => s2V.Trim()).ToArray();
        float number;
        if (Xt.Length == Yt.Length)
        {
            int i = 0;
            Xi = new float[Xt.Length];//<---properly initializing the array.
            foreach (var value in Xt)
            {

                // Console.WriteLine("l:"+Xt.Length+" "+Xt[i]+"+");
                if (Xt[i] != null)
                {
                    Xi[i] = float.Parse(Xt[i]);
                }
                //  Yi[i] = float.Parse(Yt[i]);
                i++;

            }

Thanks to MarcinJuraszek.

C# - NullReferenceException when attempting to parse a string to float in an array

1 Answers1