Editing Idiom 13 : Iterate over map keys and values

Idiom

# 13 Iterate over map keys and values

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Lead paragraph

Print each key _k with its value _x from an associative array _mymap

Implementation

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Imports

Code

int[string] mymap = ["Hello":1 , "World":2];
foreach (k, v; mymap)
    writeln("Key: ", k, " Value: ", v);

Documentation URL

Original attribution URL

Online demo

Edit summary

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Be concise.

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Please try to avoid dependencies to third-party libraries and frameworks.

Other implementations

for (Map.Entry<Object, Object> entry : mymap.entrySet()) {
    Object k = entry.getKey();
    Object x = entry.getValue();
    System.out.println("Key=" + k + ", Value=" + x);
}

Origin

import "fmt"

for k, x := range mymap {
  fmt.Println("Key =", k, ", Value =", x)
}

Demo

mymap.each {|k, x| puts "Key= #{k}  Value=#{x}"}

while ( ($k,$v) = each %mymap) {
    print "Key=$k, Value=$v\n";
}

for (k in mymap) {
   if (mymap.hasOwnProperty(k))
      console.log("key="+k+", value="+mymap[k]);
}

use std::collections::BTreeMap;

for (key, val) in &mymap {
    println!("Key={key}, Value={val}", key=key, val=val);
}

Demo

foreach ($mymap as $k=>$x)
{
    echo "Key=$k, Value=$x <br>";
}

from __future__ import print_function

for k, v in mymap.items():
	print(k, v)

mymap.forEach((k, v) => print('Key=$k, Value=$v'));

Demo

uses fgl;
type TMyMap = specialize TFPGMap<String, Integer>;

for i := 0 to mymap.Count - 1 do
  WriteLn(mymap.Keys[i], '=', mymap.Data[i]);

Enum.each(mymap, fn({k, x}) ->
  IO.puts("#{k} => #{x}")
end)

Demo
Doc

import Data.List (intercalate)
import qualified Data.Map as Map

let f k v = [show k, " = ", show v]
    mapped = Map.mapWithKeys f mymap
in putStrLn $ intercalate "," $ mapped

for {k, x} <- mymap do
  IO.puts("#{k} => #{x}")
end

Demo

maps:fold(
	fun(K, V, ok) ->
		io:format("~p: ~p~n", [K, V])
	end, ok, MyMap).

Demo
Doc

for k, x in pairs(mymap) do
	print('Key: '..k..', Value: '..x)
end

#include <iostream>

for (const auto& kv: mymap) {
	std::cout << "Key: " << kv.first << " Value: " kv.second << std::endl;
}

forall(get_dict(K, D, V),
       format("~w:~w~n", [K, V]))

Demo
Doc

val x = Map("a" -> 1, "b" -> 2, "c" -> 3)
x.foreach{ case (key, value) => println(s"$key => $value")}

foreach(var entry in map)
{
    Console.WriteLine("Key=" + entry.Key + ", Value=" + entry.Value);
}

with Ada.Containers.Indefinite_Hashed_Maps;
with Ada.Strings.Hash;

use Ada.Containers;

for C in My_Map.Iterate loop
   Put_Line ("Key = " & Key (C) & ", Value = " & Element (C));
end loop;

(doseq [k {:a "x" :b "y" :c "z"}] (prn k))

#include <iostream>

for (const auto& [key, value]: mymap) {
	std::cout << "Key: " << key << " Value: " value << '\n';
}

Preview