String Manipulation
Strings?
Strings?
In C#, you can use strings as array of characters, However, more common practice is to use the string keyword to declare a string variable. The string keyword is an alias for the System.String class.
Creating a String Object
Creating a String Object
- By assigning a string literal to a String variable
- By using a String class constructor
- By using the string concatenation operator (+)
- By retrieving a property or calling a method that returns a string
- By calling a formatting method to convert a value or an object to its string representation
Example
Example
using System;
namespace StringApplication {
class Program {
static void Main(string[] args) {
//from string literal and string concatenation
string fname, lname;
fname = "Rowan";
lname = "Atkinson";
char []letters= { 'H', 'e', 'l', 'l','o' };
string [] sarray={ "Hello", "From", "Tutorials", "Point" };
string fullname = fname + lname;
Console.WriteLine("Full Name: {0}", fullname);
//by using string constructor { 'H', 'e', 'l', 'l','o' };
string greetings = new string(letters);
Console.WriteLine("Greetings: {0}", greetings);
//methods returning string { "Hello", "From", "Tutorials", "Point" };
string message = String.Join(" ", sarray);
Console.WriteLine("Message: {0}", message);
//formatting method to convert a value
DateTime waiting = new DateTime(2012, 10, 10, 17, 58, 1);
string chat = String.Format("Message sent at {0:t} on {0:D}", waiting);
Console.WriteLine("Message: {0}", chat);
}
}
}
Properties of the String Class
Properties of the String Class
- Chars - Gets the Char object at a specified position in the current String object.
- Length - Gets the number of characters in the current String object.
Comparing Strings
Comparing Strings
using System;
namespace StringApplication {
class StringProg {
static void Main(string[] args) {
string str1 = "This is test";
string str2 = "This is text";
if (String.Compare(str1, str2) == 0) { // Using Compare method
Console.WriteLine(str1 + " and " + str2 + " are equal.");
} else {
Console.WriteLine(str1 + " and " + str2 + " are not equal.");
}
Console.ReadKey() ;
}
}
}
String Contains String
String Contains String
using System;
namespace StringApplication {
class StringProg {
static void Main(string[] args) {
string str = "This is test";
if (str.Contains("test")) { // Using the Contains method
Console.WriteLine("The sequence 'test' was found.");
}
Console.ReadKey() ;
}
}
}
Getting a Substring
Getting a Substring
using System;
namespace StringApplication {
class StringProg {
static void Main(string[] args) {
string str = "Last night I dreamt of San Pedro";
Console.WriteLine(str);
string substr = str.Substring(23); // Using the Substring method
Console.WriteLine(substr);
}
}
}
Joining Strings
Joining Strings
using System;
namespace StringApplication {
class StringProg {
static void Main(string[] args) {
string[] starray = new string[]{"Down the way nights are dark",
"And the sun shines daily on the mountain top",
"I took a trip on a sailing ship",
"And when I reached Jamaica",
"I made a stop"};
string str = String.Join("\n", starray); // Using the Join method
Console.WriteLine(str);
}
}
}