"Learning Notes" C # List

Tag: Std Space name Lin Specifies to perform the Star Line pre

• List
  • List is a strongly typed listing
  • List is better than ArrayList and is type-safe in most cases
• The difference between ArrayList and List
  • 1. ArrayList no restrictions on the type of element
  • 2. Because ArrayList has no restrictions on the types of elements, these elements are stored as Object type objects
  • 3. ArrayList is less efficient when used
• List usage
  • Adding elements using the Add () method
  • Inserting elements using the Insert () method
  • Insert the string "Star" into the position labeled 1
  • Remove the specified element using the Remove () method
  • Use the RemoveAt () method to delete an element that specifies the location of the subscript
  • Use the Count property to get the number of elements in the current list
  • Use the contains () method to determine whether the specified element exists in the list
  • You can use the subscript to access the elements in the list
  • Empty the list only with clear ()
• 　　

  1 usingSystem;2 usingSystem.Collections;3 //using generic collections requires first introducing namespaces4 usingSystem.Collections.Generic;5 6 namespaceListdemo7 {8     class Program9     {Ten         Static voidMain (string[] args) One         { A             //1. Declaring a List object arr -list<string> arr =Newlist<string>(); -             //There are no restrictions on element types in ArrayList, list has restrictions on element types the             //adding elements using the Add () method -Arr. ADD ("Hello"); -Arr. ADD (" World"); -Arr. ADD ("Li"); +  -             //inserting elements using the Insert () method +             //Insert the string "Star" into the position labeled 1 AArr. Insert (1,"Star"); at  -             //Remove the specified element using the Remove () method -Arr. Remove ("Hello"); -             //Use the RemoveAt () method to delete an element that specifies the location of the subscript -Arr. RemoveAt (1); -  in             //use the Count property to get the number of elements in the current list -             intc =arr. Count; to  +             //use the Contains () method to determine whether the specified element exists in the list -             BOOLb = arr. Contains ("Star"); the  *             if(b) $             {Panax NotoginsengConsole.WriteLine ("Star exists in the list"); -             } the             Else +             { AConsole.WriteLine ("Star does not exist in list"); the             } +             //you can use the subscript to access the elements in the list -arr[0] ="Hi there! "; $             stringstr = arr[1]; $ Console.WriteLine (str); -  -             //empty the list only with clear () the arr. Clear (); - Wuyi             //the difference between ArrayList and List the             //1. ArrayList no restrictions on the type of element -ArrayList A =NewArrayList (); WuA.add ("Hello"); -A.add ( -); AboutA.add (154.22f); $  -             //2. Because ArrayList has no restrictions on the types of elements, these elements are stored as Object Type objects -             strings = convert.tostring (a[0]); -             stringS1 = (string) a[0]; A             //A[0] is an object type +  the             //3. ArrayList is less efficient when used -         } $     } the}

"Learning Notes" C # List