D3.js | d3.map.set() Function

The map.set() function in D3.js used to set the values for the specified key string in to the created map. Syntax:

d3.map.set(key, value);

Parameters: This function accepts two parameters which are illustrated below:

key: This is the key string.
value: This is the corresponding value for each key string.

Return Value: This function does not return any values. Below programs illustrate the d3.map.set() function in D3.js: Example 1:

javascript

<!DOCTYPE html>
<html>

<head>
   <title>d3.map.set() function</title>

   <script src = "https://d3js.org/d3.v4.min.js"></script>
</head>
   
<body>
  
  <script>
    
     // Creating a map
     var map = d3.map()
     
     // setting the value for the specified key string
     // into above map
     .set("a", 1).set("b", 2).set("c", 3);

     // Getting the value for the specified key string
     A = map.get("a"); 
     B = map.get("c"); 
    
     // Printing the output of values
     console.log(A);
     console.log(B);
  </script>
</body>

</html>

Output:

1
3

Example 2:

javascript

<!DOCTYPE html>

<html>

<head>
   <title>d3.map.set() function</title>

   <script src = "https://d3js.org/d3.v4.min.js"></script>
</head>

<body>
  
  <script>
    
     // Creating a map and setting the value
     // for the specified key string
     var map = d3.map().set("Geeks", 1).set("Geek", 2).set("gfg", 3);

     // Getting the value for the specified key string
     A = map.get("Geek"); 
     B = map.get("c"); 
    
     // Printing the output of values
     console.log(A);
     console.log(B);
  </script>
</body>

</html>

Output:

2
undefined

Note: In the above code, the string "c" is not present in the created map that is why undefined is printed as output. Ref: https://devdocs.io/d3~5/d3-collection#map_set

D3.js | d3.map.set() Function

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