String, character array, character pointer

 
 

  
  
// String and character array
  
  
Var
  
  
Arr: array [0 .. 5] of Char;
  
  
Str: string;
  
  
Begin
  
  
{The String constant can be directly assigned to the character array, but not the character array}
  
  
Arr: = 'delphi ';
  
  
ShowMessage (arr); {Delphi}
  
  

  
  
{Character Arrays can be directly assigned to string variables}
  
  
Str: = arr;
  
  
ShowMessage (str); {Delphi}
  
  

  
  
{But cannot assign a string variable to the character array}
  
  
// Arr: = str; {error}
  
  

  
  
{In fact, the string also contains an array of characters, so it can be accessed by indexing, but its index starts at 1}
  
  
ShowMessage (str [1]); {D}
  
  
ShowMessage (arr [0]); {D}
  
  
End;
  
  
------------------------------------------------------------------------------ // Character pointer and character array
  
  
Var
  
  
Arr: array [0 .. 6] of Char;
  
  
P: PChar;
  
  
Begin
  
  
Arr: = 'delphi ';
  
  

  
  
{If the character array is directly given to the character pointer, the result is not insurance, because the character pointer should end with a blank character (#0}
  
  

  
  
{Add the last element of the array to #0}
  
  
Arr [Length (arr)-1]: = #0;
  
  
P: = arr;
  
  
ShowMessage (p); {Delphi}
  
  

  
  
{What If I give #0 to the center ?}
  
  
Arr [3]: = #0;
  
  
P: = arr;
  
  
ShowMessage (p); {Del; truncated}
  
  
End;