C # Regular Match (extract number from String) and C # "rounding"

This article introduces a regular small instance, which is extracted using the C # syntax to match the numbers in the string. and introduce the "rounding" in C # numeric calculations. C # Regular matching numbers

This is the instance code that extracts the number (including decimals) in the string :

    String str = "Discount 60,000";
    /**  \\d+\\.? \\d*
    * \d indicates
    the number * + indicates that the preceding number has one or more (at least one occurrence)
    * \. Here is the point to note that. Represents any atom, which is escaped here to represent a simple decimal place
    *? represents 0 or 1
    * * means 0 times or more Times
    /Regex r = new Regex ("\\d+\\.") \\d* ");
    BOOL IsMatch = R.ismatch (str);
    MatchCollection MC = r.matches (str);

    string result = String. Empty;
    for (int i = 0; I < MC. Count; i++)
    {
        results = mc[i];//Match result is a complete number, this can not do the concatenation of the
    }
    Console.WriteLine (outcome);

Note that translating the decimal point is easy to ignore

C # "Rounding" Calculation processing

C # preserves a decimal, rounded

result = "3.55";
Use the Math.Round method
Decimal d = math.round (Convert.todecimal (Result), 1, Midpointrounding.awayfromzero);
Console.WriteLine (D.tostring ());

C # Extracts the number from the string, and after rounding, replaces the original number

String str = "Discount 59,950";
Regex r = new Regex ("\\d+\\.") \\d* ");
string result = String. Empty;


if (R.ismatch (str))
{
    MatchCollection mc = r.matches (str);
    String temp = mc. Count > 0? Mc[0]. ToString (): "";
    String show = Math.Round (Convert.todecimal (temp), 1, Midpointrounding.awayfromzero). ToString ();
    Console.WriteLine (show);
    result = Regex.Replace (str, "\\d+\\.") \\d* ", show);
}
else
{result
    = str;
}

Console.WriteLine (result);