C# Basics-Part 5(Working with strings)

Most of the time in our automation project we will end up dealing with strings, that's the reason we will spend some time talking about strings in this lecture.

Before we proceed we will talk about types first.
Types in .Net can be either value or reference type

Value types 
They store data directly. example int, decimal etc.

int i = 100;

Here variable i stores the value 100

Reference types
They store references to their data. example object, string etc

string str = "Hello I am amit";

 Here str variable stores address of memory location which stores the actual "Hello I am amit" string;

string
The string is a reference type and is immutable ie contents of strings cannot be changed after a string is created.

string str = "Hello I am amit";
char[] strLetters = { '1', 'A', 'B' };
string str1 = new string(strLetters);

We can use the new keyword to create string object when initializing a string with an array of chars

String concatenation

string s1 = "String1 ";
string s2 = "String2";
s1 += s2;
Console.Write(s1);

//Output: String1 String2

The += operator creates a new string that contains the combined contents.

Regular and Verbatim String Literals

string s1 = "Line1 \r\n Line2 ";
string s2 = @"Line1 \r\n Line2 ";
 
Console.WriteLine("Regular string: "+s1);
Console.WriteLine("Verbatim string: " + s2);
Console.Read();

Output:

Regular string: Line1
 Line2
Verbatim string: Line1 \r\n Line2

In regular string characters are processed  however if you do not want to process the characters in the string then you can use Verbatim string

Handling nulls

string s1 = " ";
string s2 = null;
 
var result1 = string.IsNullOrWhiteSpace(s1);
var result2 = string.IsNullOrEmpty(s2);
 
Console.WriteLine("Result1: " + result1);
Console.WriteLine("Result2: " + result2);
Console.Read();

Output:

Result1: True
Result2: True

Format Strings

There are multiple ways you can format the strings, check below code

String interpolation was introduced in C# 6.0, achieves the same results as String.Format, however, helps to improve code readability and ease of use.

String Builder

We discussed earlier that strings as immutable ie when we concatenate two strings it will create a new string.

So if you are working on string manipulation where you change or concatenate string multiple times, it better if we can have a mutable string which can be changed without creating a new string.

String Builder class helps us to deal with strings as if they are mutable and allow an operation like concatenation without creating a new string.

Below example code

StringBuilder stringBuilder = new StringBuilder("Initial String");
for(int i=0;i<10;i++)
{
stringBuilder.Append(i);
stringBuilder.Append("_");

 }
Console.WriteLine(stringBuilder);

Here we are creating only one string and appending the contents in the loop. making our code more efficient