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Accepted
Claudio
Asked: 2020-05-27 08:33:41 +0800 CST 2020-05-27 08:33:41 +0800 CST

How to know the position of a decimal point in a String?

  • 772

I need to know in which position is the decimal point in my String, for example:

1,500(string string) in this case the "." would be at position [1].

I'm trying this but it doesn't work:

public int funcion(String number)
{
   int tam = number.Length;       
   int pos = 0;

    for (int i = 0; i < tam; i++)
    {
        if (number[i].Equals("."))
        {
            return pos;                   
        }
        pos++;
    }

    return pos = -1;
}
c#

3 Answers

  1. You are comparing against a string using "". You have to use ' since what you want is a char.

    • 4

  2. Although the result is correct, you can also use the method IndexOf:

    public int funcion(string number)
{
    return number.IndexOf('.');
}

    That method returns the index of a character in a string or -1 if it doesn't exist.

    Remember that it will throw an exception if the string is empty or null. I would leave it like this:

    public int funcion(string number)
{
    if (string.IsNullOrWhiteSpace(number))
        return -1;
    else
        return number.IndexOf('.');
}
    • 3
  3. Best Answer

    You must change "." by '.' since what is expected is a char, remember that a character of a string is going to be a char, so the same would happen with any other. Being that way:

    public int funcion(String number)
{
   int tam = number.Length;       
   int pos = 0;

    for (int i = 0; i < tam; i++)
    {
        if (number[i].Equals('.'))
        {
            return pos;                   
        }
        pos++;
    }

    return pos = -1;
}
    • 3