MaoJiuBlog

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Have a clear structure

Map 常用的属性和方法 ​

常用属性 ​

keys ​

通过keys来获取所有的 key 值

dart
var person = {"name": "John", "age": 18};
print(person.keys.toList());

values ​

通过values来获取所有的 value 值

dart
var person = {"name": "John", "age": 18};
print(person.values.toList());

isEmpty & isNotEmpty ​

通过isEmpty and isNotEmpty来判断是否为空

dart
var person = {"name": "John", "age": 18};
print(person.isEmpty); // false
print(person.isNotEmpty);  // true

常用方法 ​

remove ​

通过remove(key)来删除指定 key 的数据

dart
var person = {"name": "John", "age": 18};
person.remove('name');

addAll ​

使用addAll({...})来合并 Map 映射

dart
var person = {"name": "John", "age": 18};
person.addAll({"sex": "男"});

containsKey ​

使用containsKey来查看映射内的键(返回 true/false)

dart
var person = {"name": "John", "age": 18};
print(person.containsKey("name"));

containsValue ​

使用containsValue来查看映射内的值(返回 true/false)

dart
var person = {"name": "John", "age": 18};
print(person.containsValue("John"));