So it doesn't matter how big the dictionary is, you can instantaneously retrieve the value associated with the key. Extremely powerful.

因为你可以在线性时间，内得到想要的键对应的值,这太强大了。

麻省理工公开课 - 计算机科学及编程导论课程节选

Remember the way dictionary works, this is the key. Is the key of a value.

记住这个字典的工作原理，这是关键，它是值的关键。

麻省理工公开课 - 计算机科学及编程导论课程节选