MapExt extension Null safety

@author Barry @date 2020/9/4 describe:

on

Methods

asBean<T>(String key, dynamic toBean(Map json)) → T?
解析成 model
asBeans<T>(List<String> keys, dynamic toBean(Map json)) → T?
多字段解析成model
asBool(String key, [bool? defValue]) bool
解析成bool值
asDouble(String key, [double? defValue]) double
解析成double值
asDoubles(List<String> keys, [double? defValue]) double
多字段解析成double值
asInt(String key, [int? defValue]) int
解析成int值
asInts(List<String> keys, [int? defValue]) int
解析成ints值
asList<T>(String key, [dynamic toBean(Map json)?]) List<T>?
解析成List
asLists<T>(List<String> keys, [dynamic toBean(Map json)?]) List<T>?
多字段解析成Lists
asNum(String key) num
解析成int或者double值
asString(String key, [String? defValue]) String
单字段解析
asStrings(List<String> keys, [String? defValue]) String
多字段解析Strings
put(String key, Object? value) Map
key and value的功能
removeNull() → void
移除掉空的
removeNullOrEmpty() → void
移除null值或空值