You’ll want to use the isalpha() and isdigit() standard functions in <ctype.h>. char c=”a”; // or whatever if (isalpha(c)) { puts(“it’s a letter”); } else if (isdigit(c)) { puts(“it’s a digit”); } else { puts(“something else?”); }
Using MySQL 8.0 or higher Courtesy of michal.jakubeczy’s answer below, replacing by Regex is now supported by MySQL: UPDATE {table} SET {column} = REGEXP_REPLACE({column}, ‘[^0-9a-zA-Z ]’, ”) Using MySQL 5.7 or lower Regex isn’t supported here. I had to create my own function called alphanum which stripped the chars for me: DROP FUNCTION IF EXISTS … Read more
Pass a custom comparer into OrderBy. Enumerable.OrderBy will let you specify any comparer you like. This is one way to do that: void Main() { string[] things = new string[] { “paul”, “bob”, “lauren”, “007”, “90”, “101”}; foreach (var thing in things.OrderBy(x => x, new SemiNumericComparer())) { Console.WriteLine(thing); } } public class SemiNumericComparer: IComparer<string> { … Read more
Regex is the best tool for the job; what it should be depends on the problem specification. The following removes leading zeroes, but leaves one if necessary (i.e. it wouldn’t just turn “0” to a blank string). s.replaceFirst(“^0+(?!$)”, “”) The ^ anchor will make sure that the 0+ being matched is at the beginning of … Read more
A simple example using a regular expression which you could change to allow/disallow whatever you like. $(‘input’).on(‘keypress’, function (event) { var regex = new RegExp(“^[a-zA-Z0-9]+$”); var key = String.fromCharCode(!event.charCode ? event.which : event.charCode); if (!regex.test(key)) { event.preventDefault(); return false; } });
Algorithm To generate a random string, concatenate characters drawn randomly from the set of acceptable symbols until the string reaches the desired length. Implementation Here’s some fairly simple and very flexible code for generating random identifiers. Read the information that follows for important application notes. public class RandomString { /** * Generate a random string. … Read more
Try this function: Create Function [dbo].[RemoveNonAlphaCharacters](@Temp VarChar(1000)) Returns VarChar(1000) AS Begin Declare @KeepValues as varchar(50) Set @KeepValues=”%[^a-z]%” While PatIndex(@KeepValues, @Temp) > 0 Set @Temp = Stuff(@Temp, PatIndex(@KeepValues, @Temp), 1, ”) Return @Temp End Call it like this: Select dbo.RemoveNonAlphaCharacters(‘abc1234def5678ghi90jkl’) Once you understand the code, you should see that it is relatively simple to change it … Read more