Strings in c#
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Strings in C# can be manipulated using the System.String class. Strings can be immutable, using the standard string type, or mutable, using the StringBuilder class. Various methods like Compare(), Equals(), and == operator can be used to compare strings. Regular expressions allow searching, matching, and modifying strings using classes like Regex, MatchCollection, and Match.
![Mutable String Program
using System;
using System.Text;
class strbuild
{
public static void Main()
{
string str1,str2;
Console.WriteLine("Enter first string");
str1=Console.ReadLine();
Console.WriteLine("Enter Second string");
str2=Console.ReadLine();
StringBuilder s1 = new StringBuilder(str1);
StringBuilder s2 = new StringBuilder(str2);
//1.Appending a String
s1.Append("Smile");
// Console.WriteLine("String After Append :" +s1);
//2.Append Format
s2.AppendFormat("1)s2 after Append Format {0}",s2);
s1.AppendFormat("2)s1 after Append Format {0}",s1);
//3.Ensure Capacity
int x=s1.EnsureCapacity(30);
//4.Inserting a String
s2.Insert(3,"Life");
//5.Remove
s1.Remove(5,3);
//6.Replace
s2.Replace('A', '*');
//7.Capacity
int y= s1.Capacity;
Console.WriteLine("Capacity is"+y);
s1.Capacity=100;
y=s1.Capacity;
Console.WriteLine("New Capacity is"+y);
//8.Length
int z = s1.Length;
int v = s2.Length;
Console.WriteLine(" Length of s1 "+ z);
Console.WriteLine("Length of s2"+ v);
//9.MaxCapacity
int c= s1.MaxCapacity;
Console.WriteLine("Max Capacity"+s1);
//10.setting a character
int n=s2.Length;
s2[n-1]='@';
}
}
Dr. Neeraj Kumar
Pandey](https://image.slidesharecdn.com/strings-190212071718/85/Strings-in-c-8-320.jpg)
Strings in c#
- 1. Strings in C# Dr. Neeraj Kumar Pandey
- 2. Strings in C# In C# System.String class is used to manipulate strings. System.String is a very powerful and versatile class, but it is not by any means the only string-related class in the .NET armory. System.Text and System.Text.RegularExpression namespaces are also used in Building Strings,Formatting Expressions and Regular Expression Dr. Neeraj Kumar Pandey
- 3. Immutable Strings In this type of strings, we cannot modify the characters of a string. Dr. Neeraj Kumar Pandey
- 4. Immutable Strings Dr. Neeraj Kumar Pandey
- 5. Comparing Strings Compare() Method int n=string.Compare(s1,s2); Zero interger, if s1 is equal to s2 A positive Integer (1) , if s1 is greater than s2 A negative integer(-1), if s1 is less than s2 Equals() Method There are two versions of Equals method. They are implemented as follows:- bool b1= s2.Equals(s1); bool b2= string.Equals(s2,s1); These methods returns a Boolean value true if s1 and s2 are equal, otherwise false. The == Operator bool b3= (s1==s2); //b3 is true if they are equal We very often use such statements in decision statements, like:- if(s1==s2) Dr. Neeraj Kumar Pandey
- 6. Mutable Strings This type of strings are modifiable using the StringBuilder class. StringBuilder str1=new StringBuilder(“hello”); StringBuilder str2=new StringBuilder(); They can grow dynamically as more characters are added to them. They can grow either unbounded or up to a configurable maximum. Mutable Strings are also known as dynamic strings. Dr. Neeraj Kumar Pandey
- 7. Mutable Strings(Contd..) The System.Text namespace contains the class StringBuilder, therefore we must include the using System.Text directive for creating and manipulating mutable strings. Dr. Neeraj Kumar Pandey
- 8. Mutable String Program using System; using System.Text; class strbuild { public static void Main() { string str1,str2; Console.WriteLine("Enter first string"); str1=Console.ReadLine(); Console.WriteLine("Enter Second string"); str2=Console.ReadLine(); StringBuilder s1 = new StringBuilder(str1); StringBuilder s2 = new StringBuilder(str2); //1.Appending a String s1.Append("Smile"); // Console.WriteLine("String After Append :" +s1); //2.Append Format s2.AppendFormat("1)s2 after Append Format {0}",s2); s1.AppendFormat("2)s1 after Append Format {0}",s1); //3.Ensure Capacity int x=s1.EnsureCapacity(30); //4.Inserting a String s2.Insert(3,"Life"); //5.Remove s1.Remove(5,3); //6.Replace s2.Replace('A', '*'); //7.Capacity int y= s1.Capacity; Console.WriteLine("Capacity is"+y); s1.Capacity=100; y=s1.Capacity; Console.WriteLine("New Capacity is"+y); //8.Length int z = s1.Length; int v = s2.Length; Console.WriteLine(" Length of s1 "+ z); Console.WriteLine("Length of s2"+ v); //9.MaxCapacity int c= s1.MaxCapacity; Console.WriteLine("Max Capacity"+s1); //10.setting a character int n=s2.Length; s2[n-1]='@'; } } Dr. Neeraj Kumar Pandey
- 9. Regular Expression A regular expression may be applied to a text to accomplish tasks such as :- To locate substring and return them To modify one or more substrings and return them To identify substrings that begins with or end with a pattern of characters. To find all the words that begin with a group of characters and end with some other characters To find all the occurrences of a substring pattern. System.Text.RegualrExpressions supports a number of classes that can be used for searching, matching and modifying a text document.The important classes are:- Regex, MathCollection, Match. Dr. Neeraj Kumar Pandey
- 10. Regular Expression Program using System; using System.Text; using System.Text.RegularExpressions; class bulb { public static void Main() { string str; str= Console.ReadLine(); Regex reg= new Regex(" |, "); StringBuilder sb= new StringBuilder(); int count=1; foreach(string sub in reg.Split(str)) { sb.AppendFormat("{0}:{1}n",count++,sub); } Console.WriteLine(sb); } } Dr. Neeraj Kumar Pandey