Maps and set JS

Set

Manage data collection

const set = new Set([1, 2, 3, 4, 5]);
console.log(set);

Metody

• add(): Adds a new element to the Set.
• delete(): Removes an element from the Set.
• has(): Checks if an element exists in the Set.
• clear(): Removes all elements from the Set.
• keys() and values(): Both returns a SetIterator that contains the values of the Set. They are the same because keys() is an alias for values().
• forEach(): for iterating over the values of the Set.

WeakSets

• Memory use, na hovno

Maps

• key-value pair
• Stejný princip jako Dictionary PY

const map = new Map([
  ['flower', 'rose'],
  ['fruit', 'apple'],
  ['vegetable', 'carrot']
]);
console.log(map); // Map(3) { 'flower' => 'rose', 'fruit' => 'apple', 'vegetable' => 'carrot' }

Metody

• set(): Adds a new key-value pair to the Map.
• get(): Retrieves the value of a key from the Map.
• delete(): Removes a key-value pair from the Map.
• has(): Checks if a key exists in the Map.
• clear(): Removes all key-value pairs from the Map.

WeakMaps

• Memory use, na hovno