Copy a string: Difference between revisions

===Fixed Length String Copying.===

Src : String := "Hello";

Dest : String := Src;

Ada provides the ability to manipulate slices of strings.

Src : String "Rosetta Stone";

Dest : String := Src(1..7); -- Assigns "Rosetta" to Dest

Dest2 : String := Src(9..13); -- Assigns "Stone" to Dest2

===Bounded Length String Copying===

-- Instantiate the generic package Ada.Strings.Bounded.Generic_Bounded_Length with a maximum length of 80 characters

package Flexible_String is new Ada.Strings.Bounded.Generic_Bounded_Length(80);

Src : Bounded_String := To_Bounded_String("Hello");

Dest : Bounded_String := Src;

Ada Bounded_String type provides a number of functions for dealing with slices.

=== Unbounded Length String Copying===

-- The package Ada.Strings.Unbounded contains the definition of the Unbounded_String type and all its methods

Src : Unbounded_String := To_Unbounded_String("Hello");

Dest : Unbounded_String := Src;

=={{header|ALGOL 68}}==

=={{header|Common Lisp}}==

=={{header|D}}==

To copy a string, just use ordinary assignment:

my $new = $original;

$new = 'Goodbye.';

To create a reference to an existing string, so that modifying the referent changes the original string, use a backslash:

$$ref = 'Goodbye.';

If you want a new name for the same string, so that you can modify it without dereferencing a reference, assign a reference to a typeglob:

local *alias = \$original;

$alias = 'Good evening.';

=={{header|PHP}}==

Since strings are immutable, all copy operations return the same string. Probably the reference is increased.

>>> src = "hello"

>>> a = src

>>> src is a is b is c is d

True

To actually copy a string:

>>> a = 'hello'

>>> b = ''.join(a)

>>> b is a ### Might be True ... depends on "interning" implementation details!

False

As a result of object "interning" some strings such as the empty string and single character strings like 'a' may be references to the same object regardless of copying. This can potentially happen with any Python immutable object and should be of no consequence to any proper code.

=={{header|Scheme}}==

=={{header|Seed7}}==