📅 最后修改于: 2020-11-04 05:54:07 🧑 作者: Mango
映射是具有可变数量的键值关联的复合数据类型。映射中的每个键-值关联称为关联对。该对中的键和值部分称为元素。关联对的数量被称为地图的大小。
以下程序显示了如何使用Map数据类型的示例。
在这里，我们定义了具有2个映射的Map M1。 map_size是用Erlang定义的内置函数，可用于确定地图的大小。
-module(helloworld).
-export([start/0]).
start() ->
M1 = #{name=>john,age=>25},
io:fwrite("~w",[map_size(M1)]).
上述程序的输出如下。
2
适用于地图的其他一些方法如下。
| Sr.No. | Methods & Description |
|---|---|
| 1 |
This method is used to generate a map from a list. |
| 2 |
This method is used to find if a particular key exists in the map. |
| 3 |
This method is used to get the value of a particular key in the map. |
| 4 |
This method is used to determine if a particular key is defined as a key in the map. |
| 5 |
This method is used to return all the keys from a map. |
| 6 |
This method is used to merge 2 maps. |
| 7 |
This method is used to add a key value pair to the map. |
| 8 |
This method is used to return all the values from a map. |
| 9 |
This method is used to remove a key value from the map. |