进程字典¶

put/2

put(Key, Val) -> term()
类型
Key = Val = term()
1.没有Key对应的值:
  增加此Key,返回值为undefined
2.有此Key对应的值:
  替换此Key,返回原来的值

实例:

> X = put(name, walrus).
> Y = put(name, carpenter).
> Z = get(name).
> {X, Y, Z}.
{undefined,walrus,carpenter}

注意:

The values stored when put is evaluated within the scope of a catch are not retracted if a throw is evaluated, or if an error occurs.

get/0

get() -> [{Key, Val}]
类型:
Key = Val = term()
返回全部进程字典

实例:

> put(key1, merry).
> put(key2, lambs).
> put(key3, {are, playing}).
> get().
[{key1,merry},{key2,lambs},{key3,{are,playing}}]

get/1

get(Key) -> Val | undefined
类型:
Key = Val = term()
Returns the value Val associated with Key in the process dictionary, or undefined if Key does not exist. Example:

实例:

> put(key1, merry).
> put(key2, lambs).
> put({any, [valid, term]}, {are, playing}).
> get({any, [valid, term]}).
{are,playing}