12.字典

字典

字典，也称为键值存储，是包含键引用的值的关联容器。

var simpleDictionary = {"name": "John"}

在上面的代码中， key name，而 value 是”John”
除了字符串之外，您还可以使用其他数据类型作为键：

var integerDictionary = {1: "John"}
var floatDictionary = {2.13: "Jane"}
var booleanDictionary = {true: "Sarah"}

访问字典

# Create Dictionaries
var simpleDictionary = {"name": "John"}
var integerDictionary = {1: "Jane"}
var floatDictionary = {2.13: "Josh"}
var booleanDictionary = {true: "Sarah"}
# Retrieve values
var getJohn = simpleDictionary["name"] # "John"
var getJane = integerDictionary[1] # "Jane"
var getJosh = floatDictionary[2.13] # "Josh"
var getJohn = booleanDictionary[true] # "Sarah"
# You can use dot notation if retrieving string keys
var getJohnAgain = simpleDictionary.name # "John"

将值分配给现有键

var simpleDictionary = {"name": "John"}
# One way
simpleDictionary["name"] = "Jane"
# Another way
simpleDictionary.name = "Jane Doe"

创建新的键值对

var simpleDictionary = {"name": "Jane"}
simpleDictionary["birthdate"] = "December 2020"
simpleDictionary.age = 0

比较字典键值对

如果用比较运算符比较字典，即使比较的字典完全相同，也会返回 false：

var simpleDictionary = {"name": "Jane"}
var sameDictionary = {"name": "Jane"}
if(simpleDictionary == sameDictionary):
    # Block of code never runs

要在 coparing 字典时获得所需的结果，请使用以下hash方法：

var simpleDictionary = {"name": "Jane"}
var sameDictionary = {"name": "Jane"}
if(simpleDictionary.hash() == sameDictionary.hash()):
    # Block of code runs

删除键值对

要删除键值对，请使用以下erase方法：

var simpleDictionary = {"name": "Jane"}
simpleDictionary.erase("name")