Swipe values with keys, -> Map vs Object in Javascript

I was trying to swap keys with values in Map and Object.

In Map it goes in an infinite loop, but in Object it goes in a finite loop. I don’t know why is that happening. Please help!

Here is the Code.

const obj = { 1: "one", 2: "two" };
const map = new Map([
  [1, "one"],
  [2, "two"],
]);

for (const [key, value] of map) {  // Goes Infinite Loop
  map.set(value, key);
  map.delete(key);
}
console.log(map); // you will never get this response

for (const [key, value] of Object.entries(obj)) { // Goes Finite 
  obj[value] = key
  delete obj[key];
}
console.log(obj); // you will get the response