Usage scenarios of newly added Map and Set data structures in ES6

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ES6 introduces two new data structures, Map and Set, which solve different problems and have unique characteristics. Let’s take a look at each of them and their usage scenarios.

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⭐ Map data structure

Map is a collection of key-value pairs, where each key is unique. Its main features include:

1. Keys can be of any data type : Unlike objects, the keys of a Map can be of any data type, including strings, numbers, objects, etc.

2. Keep the order of key-value pairs : Map will maintain the order of key-value pairs in the order they were inserted.

3. Fast lookup and deletion : Map provides an efficient way to lookup and delete key-value pairs.

4. Iterable : Map supports iteration and can easily traverse the key-value pairs in it.

5. Any number of key-value pairs can be stored : Unlike objects, Maps are not slowed down by containing a large number of key-value pairs.

Example of usage scenario:

// 创建一个 Map
const userRoles = new Map();

// 添加键值对
userRoles.set('john', 'admin');
userRoles.set('jane', 'editor');

// 获取键值对
console.log(userRoles.get('john')); // 输出 "admin"

// 检查键是否存在
console.log(userRoles.has('jane')); // 输出 true

// 删除键值对
userRoles.delete('john');

// 迭代 Map
for (const [user, role] of userRoles) {
    
    
  console.log(`${
      
      user} 的角色是 ${
      
      role}`);
}

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⭐Set data structure

A Set is a non-repeating collection of values. Its main features include:

1. Unique value : The value in the Set is unique and will not contain duplicate values.

2. Duplicate values ​​not allowed : Set will automatically ignore when attempting to add duplicate values.

3. Fast lookup : Set provides efficient value lookup methods.

4. Iterable : Set also supports iteration, allowing easy traversal of its values.

Example of usage scenario:

// 创建一个 Set
const uniqueNumbers = new Set();

// 添加值
uniqueNumbers.add(1);
uniqueNumbers.add(2);
uniqueNumbers.add(3);
uniqueNumbers.add(2); // 重复值将被忽略

// 检查值是否存在
console.log(uniqueNumbers.has(2)); // 输出 true

// 删除值
uniqueNumbers.delete(1);

// 迭代 Set
for (const number of uniqueNumbers) {
    
    
  console.log(number);
}

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⭐Map and Set usage scenarios

• Usage scenarios of Map : It is suitable for situations where keys need to be mapped to values, such as managing user permissions, storing associations between objects, etc.

• Usage scenarios of Set : Suitable for situations where you need to store a set of unique values, such as removing duplicates in an array, tracking a set of unique items, etc.

These new data structures provide more flexibility and performance and can help developers handle various complex data structure and algorithm problems more easily.

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