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Programming-Idioms

  • C++
  • Java

Idiom #266 Repeated string

Assign to the string s the value of the string v repeated n times, and write it out.

E.g. v="abc", n=5 ⇒ s="abcabcabcabcabc"

for (int i=0;i<n;i++){
          s = s+v;
      }
System.out.println(s);

s+v is the same as s.concat(v) and can be used interchangeably
import static java.util.stream.Collectors.joining;
import static java.util.stream.Stream.generate;
String s = generate(() -> v)
    .limit(n)
    .collect(joining());
String s = v.repeat(n);

System.out.println(s);

Java 11+
#include <string>
s.reserve(v.size() * n);
for (size_t i = 0; i < n; ++i)
  s.append(v);
with Ada.Strings.Fixed;
use Ada.Strings.Fixed;
S : constant String := N * V;
New implementation...
< > ⌨
tkoenig 
for (int i=0;i<n;i++){
          s = s+v;
      }
System.out.println(s);
String s = generate(() -> v)
    .limit(n)
    .collect(joining());
String s = v.repeat(n);

System.out.println(s);
s.reserve(v.size() * n);
for (size_t i = 0; i < n; ++i)
  s.append(v);
use Ada.Strings.Fixed;
S : constant String := N * V;
char *s = calloc(strlen(v) * n + 1, 1);
for(int i = 0; i < n; ++i) strcat(s, v);
(def s (apply str (repeat n v)))
(def s (clojure.string/join "" (repeat n v)))
string s = string.Create(v.Length * n, (v, n), static (span, state) =>
{
    var (v, n) = state;
    var originSpan = v.AsSpan();
    for (var i = 0; i < n; i++)
    {
        var subSpan = span[(i * originSpan.Length)..];
        originSpan.CopyTo(subSpan);
    }
});

var sb = new StringBuilder();
for(var i = 0; i < n; i++)
	sb.Append(v);

var s = sb.ToString();
var s = string.Concat(Enumerable.Repeat(v, n));
var s = v * n;
s = String.duplicate(v, n)
S = lists:concat(lists:duplicate(N, V)).
character(len=:), allocatable :: s,v
integer :: n
s = repeat(v,20)
write (*,'(A)') s

s := strings.Repeat(v, n)
fmt.Println(s)
s = concat $ replicate n v
const s = v.repeat(n)
val s = v.repeat(n)
println(s)
(do ((i 0 (+ i 1 )))( (= i n) s)
  (setf s (concatenate 'string s v)))
s = string.rep(v, n)
$s = str_repeat($v, $n);
echo $s;
s := DupeString(v, n);
writeln(s);
s:= '';
for i := 1 to n do s := s + v;
writeln(s);
my $s = $v x $n;
s = v * n
s = ''.join(repeat(v, n))
s = v * n
let s = v.repeat(n);