Return to Answer

added 187 characters in body

edited Jan 18, 2012 at 0:22

83.3k
24
238
312

You asked about other modern OO languages? Well, Delphi avoids this problem entirely by having string be a primitive, not an object. So an array of strings is exactly an array of strings and nothing else, and any operations on them are as fast as native code can be, with no type checking overhead.

However, string arrays are not used very often; Delphi programmers tend to favor the TStringList class. For a minimal amount of overhead it provides a set of string-group methods that are useful in so many situations that the class has been compared to a Swiss Army Knife. So it's idiomatic to use a string list object instead of a string array.

As for other objects in general, the problem does not exist because in Delphi, like in C++, arrays are not covariant, in order to prevent the kind of type system holes described here.

You asked about other modern OO languages? Well, Delphi avoids this problem entirely by having string be a primitive, not an object. So an array of strings is exactly an array of strings and nothing else, and any operations on them are as fast as native code can be, with no type checking overhead.

However, string arrays are not used very often; Delphi programmers tend to favor the TStringList class. For a minimal amount of overhead it provides a set of string-group methods that are useful in so many situations that the class has been compared to a Swiss Army Knife. So it's idiomatic to use a string list object instead of a string array.

You asked about other modern OO languages? Well, Delphi avoids this problem entirely by having string be a primitive, not an object. So an array of strings is exactly an array of strings and nothing else, and any operations on them are as fast as native code can be, with no type checking overhead.

However, string arrays are not used very often; Delphi programmers tend to favor the TStringList class. For a minimal amount of overhead it provides a set of string-group methods that are useful in so many situations that the class has been compared to a Swiss Army Knife. So it's idiomatic to use a string list object instead of a string array.

As for other objects in general, the problem does not exist because in Delphi, like in C++, arrays are not covariant, in order to prevent the kind of type system holes described here.

answered Jan 17, 2012 at 23:01

83.3k
24
238
312

You asked about other modern OO languages? Well, Delphi avoids this problem entirely by having string be a primitive, not an object. So an array of strings is exactly an array of strings and nothing else, and any operations on them are as fast as native code can be, with no type checking overhead.

However, string arrays are not used very often; Delphi programmers tend to favor the TStringList class. For a minimal amount of overhead it provides a set of string-group methods that are useful in so many situations that the class has been compared to a Swiss Army Knife. So it's idiomatic to use a string list object instead of a string array.