checking numbers in strings

Questions & Answers
1

Hi. first of all i’m beginner.
i’m using c# and i need help about this problem. i need to check if the first part of an string Variable is equel to for example “Hello” and Its continuation are numbers(if it continued by numbers. any number) do something. now i know for the first part we have stringVar.StartsWith() , but what about the numbers part? do we have any symbol in strings like #?&$ for representing numbers or any methods? help me please what code should i use?
imagination:

if(stringVar.StartsWith("Hello") && numbers check part)
{
  do something
}
else
{
  do something else
}

think our string variable is “Hello754”.
note: the optimized Performance for this part of my game is very important and don’t tell me about going through too many loops and arrays or…
I welcome and appreciate any help :slight_smile:

2

If I understand what you need, you should be able to achieve this with a Regular expression.

First you’ll need to include the System.Text.RegularExpressions namespace.

Then you should be able to run this check on your string

if(Regex.IsMatch("Hello754",  @"^Hello[0-9]+") //This will return true if the string is the word "Hello" followed by number characters

If you’d like to learn more about Regex so you can create a system that maybe works more the way you want it to, I’d suggest checking out Daniel Shiffmans series on it.

3

what about this? :slight_smile:
since my question was under moderator review too long, i had time to search in string methods and write this code. this is working perfectly to me:

int result;
if(stringVar.StartsWith("Hello") && int.TryParse(stringVar.Substring(5), out result))
{
     Debug.Log("i'm Hello with my numbers friends");
}

hope it helps anyone else.