There is a requirement where we are supposed to replace space * with an underscore. An example of a requirement is given below:
C# Check string has special characters or not
Input : rake *s@hr:d
Output: True
Check whether the string has special chars including number(s)
Input : rake *s@hr:d123
Output: True
C# How to replace the special characters(including numbers) with ‘_’
Input : rake *s@hr:d12
Output: rake__s_hr_d__
Write method to replace all space chars with %20
Input : rake s d
Output: rake%20s%20d
c# code to check if string contains special characters or not without using functions
Input : rake *s@hr:d
Output: true
c# code to check if string contains special characters or not and replace with underscore or %20(Including space)without using functions
Input : rake *s@hr:d
Output: rake%20s%20hr%20d
Solution:
Error: The type or namespace name ‘Regex’ could not be found (are you missing a using directive or an assembly reference?
If you found the error, Add reference by right-clicking on the Regex word or enter ctrl+. or click on the bulb symbol to add the reference.
There are different ways to solve this, By using Regex, This could be matched against the text input so that by using regular expression we can achieve all of the above things mentioned in the problem's section by using regular expression.
Approach 1: Code snippet is to check whether the string contains a special character(s) or not and, replace them with _ (underscore).
The below code snippet is to check whether the string contains a special character or not, new Regex(“[^A-Za-z0-9]”), the pattern is used to check whether the string contains special characters or not. IsMatch() the function checks the string and returns True then it replaces the special character with ‘_’.
Approach 2: Code snippet is to check whether the string contains a special character or not
The below code snippet is to check whether the string contains a special character or not. new Regex(“[^A-Za-z0-9]”) the pattern is used to check whether the string contains special characters or not. IsMatch() function checks the string and returns True if it contains a special character.
Approach 3: Code snippet is to check whether the string contains a special character(including number ) or not
The below code snippet is to check whether the string contains a special character(including number ) or not. new Regex(“[^A-Za-z0-9]”) the pattern is used to check whether the string contains special characters or not. IsMatch() function checks the string and returns True if the string contains a special character. int.TryParse(str, out int n) the method returns True if the string contains the number(s).
Approach 4: Code snippet is to check check and replace special characters(including number(s))
The below code snippet is to check and replace special characters(including number(s)). new Regex(“[^A-Za-z0-9]”) the pattern is used to check whether the string contains special characters or not. IsMatch() function checks the string and returns True if the string contains a special character. int.TryParse(str, out int n) the method returns True if the string contains the number(s). Here either one of the conditions passes then the character will be replaced by ‘_’.
Approach 5: Code snippet is to replace all space chars with %20 of a char array
Here the below code block replace all space chars with %20 and the method to accept char[] array and replaces the space to %20 and returns the char array result.
Approach 6: Check if string contains special characters or not without using functions
The below code approach will check every character and is a special character and returns a boolean true or false.
Approach 7: check if the string contains special characters or not and replace with underscore or %20(Including space)without using functions
The below code approach will check every character and is a special character and replace it with %20including number or space and returns a new string.
Conclusion
A regular expression is a pattern that could be matched against an input text. By using the Regex pattern matching technique we achieved that string contains special characters or not, replaced the special character text with some other value (like ‘_’). I hope you find them helpful.