JavaScript: Map.prototype.keys(): Get all the keys of map

Map.prototype.keys()

This method returns an iterator, that contains all the keys of map.

  var keys = map.keys();

 

  for(var key of keys){

    console.log(key + " : " + map.get(key));

  }

Find the below working application.

HelloWorld.js

function printMap(map){
  console.log("***************************");
  console.log("Total elements in countriesMap are : " + map.size);
  
  var keys = map.keys();
  
  for(var key of keys){
    console.log(key + " : " + map.get(key));
  }
}

var countriesMap = new Map();

countriesMap.set("Bahrain", "Manama");
countriesMap.set("Cameroon", "Yaounde");
countriesMap.set("Norway", "Oslo");
countriesMap.set("India", "New Delhi");
countriesMap.set("Russia", "Moscow");
countriesMap.set("Spain", "Madrid");

printMap(countriesMap);

Output

***************************

Total elements in countriesMap are : 6

Bahrain : Manama

Cameroon : Yaounde

Norway : Oslo

India : New Delhi

Russia : Moscow

Spain : Madrid

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