Remove Special Characters From A Mobile Number With C#

Sometimes, we need to remove all special characters from a mobile number and store just numbers only. The simplest way to do so is, look for the special characters and remove them from the number. 
 
Here is a method that removes special characters, space, +, and - from a number. You can use the same approach to remove any character a number. If your string has other characters, add them to this list.  
  1. private string convert_to_number(string No)  
  2. {  
  3. string mobileno = "";  
  4. //remove special characters  
  5. foreach (char ch in No)  
  6. {  
  7. if (ch != ' ' && ch != '+' && ch != '-')  
  8. {  
  9. mobileno = mobileno + ch.ToString();  
  10. }  
  11. }  
  12. //convert to 10 digit  
  13. if (mobileno.Length > 10)  
  14. {  
  15. mobileno = mobileno.Substring(mobileno.Length - 10, 10);  
  16. }  
  17. return (mobileno);  
  18. }  
Another way to validate a mobile number is to use a regular expression. Here is the mobile number validation regular expression: 
  1. Regular expression:  
  2.   
  3. / ^((\+){0,1}91(\s){0,1}(\-){0,1}(\s){0,1}){0,1}9[0-9](\s){0,1}(\-){0,1}(\s){0,1}[1-9]{1}[0-9]{7}$/ (without +91 or 0)  
  4.   
  5. /^((\\+91-?)|0)?[0-9]{10}$/ (with or without +91 or 0)  
  6.   
  7. ^((\\+|00)(\\d{1,3})[\\s-]?)?(\\d{10})$/ (split the number and the country code)  
Here are more detailed tutorials on the same:
 
 
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