User FAQs

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1) What is the difference between System.String and System.Text.StringBuilder ?
System.Text.StringBuilder is not an immutable data type and is therefore more efficient when a lot of string manipulations are required.
System.String is an immutable data type.

System.Text.StringBuilder myStringBuilder; 
myStringBuilder = new System.Text.StringBuilder("some text"); 
myStringBuilder.Append("more"); 
myStringBuilder.Replace("e","a"); 

2) Can you give an example of string interpolation ?
Use string interpolation to concatenate short strings, as shown in the following code.
You should use this instead of composite format strings.

name.FirstName = "Better"; 
name.LastName = "Solutions"; 
string result = $"{name.FirstName}, {name.LastName}"; 
Console.Writeline(result);    // "Better, Solutions" 

3) Can you give an example of using a composite format string ?

name.FirstName = "Better"; 
name.LastName = "Solutions"; 
string composite = "{0}, {1}"; 
string result = String.Format(composite, name.FirstName, name.LastName); 
Console.Writeline(result);    // "Better, Solutions" 

4) What is the fastest way to append strings in a loop ?
To append strings in loops, especially when you're working with large amounts of text, use a StringBuilder object.

var phrase = "la"; 
var manyPhrases = new StringBuilder(); 
for (var i = 0; i < 10000; i++) 
{ 
    manyPhrases.Append(phrase); 
} 

5) What does the @ prefix mean at the start of a text string ?
When you use a "@" prefix you do not have to escape any special characters.
For example you do not have to use a double slash \\ when you want to include a slash.
However you do have to use two double quotes to input a double quote.

string myString = "C:\\temp" 
string myString = @"C:\temp" 
string myString = @"You need a double quote "" for a double quote" 

6) How can I remove newlines (\n) from a string ?
You can use the Replace method.

string myString = myLongString.Replace("\n",""); 

7) How can I replace the /" character with just a " in a string ?
You can use the Replace method.

string myString = myLongString.Replace("\\\n","\""); 

8) How can I remove all the non UTF8 characters from a string ?
You can use encoding which is the process of transforming a set of Unicode characters into a sequence of bytes.

byte[] bytes = System.Text.Encoding.Default.GetBytes(textBefore); 
string textAfter = System.Text.Encoding.UTF8.GetString(textBefore); 

9) What syntax could you use for a multi-line string ?
All of these will work.

string str1 = @"this is a 
              multi line 

string str2 = "this is a \n" + 
              "multi line \n" + 

string str3 = "this is a " + System.Environment.NewLine + 
              "multi line "