Question

How to iterate over a map in reverse order in JavaScript

Answer 1

let mp = new Map();
   
mp.set("JavaScript", 23);
mp.set("Java", 89);
mp.set("C", 31);
mp.set("C++", 93);
mp.set("PHP", 77);

const arr = Array.from(mp).reverse();

arr.forEach(([key, value]) => {
  	console.log(key, value); 
});
   
   
        
        
/*
run:
        
"PHP", 77
"C++", 93
"C", 31
"Java", 89
"JavaScript", 23
        
*/

 

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Answer 2

let mp = new Map();
   
mp.set("JavaScript", 23);
mp.set("Java", 89);
mp.set("C", 31);
mp.set("C++", 93);
mp.set("PHP", 77);

Array.from(mp)
   .reverse()
   .forEach(element => {
          console.log(element, element[0], element[1]); 
   });


   
        
        
/*
run:
        
["PHP", 77], "PHP", 77
["C++", 93], "C++", 93
["C", 31], "C", 31
["Java", 89], "Java", 89
["JavaScript", 23], "JavaScript", 23
        
*/

 

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