js add to map code example

Example 1: append to map javascript

var myMap = {};

myMap[newKey] = newValue;

// ...


// Another method

var myMap = new Map()
myMap.set("key0","value")
// ...
myMap.has("key1"); // evaluates to false, assuming key1 wasn't set

Example 2: javascript map

const numbers = [0,1,2,3];

console.log(numbers.map((number) => {
  return number;
}));