Instructor: 00:01 Let bindings are mutable by default. We can make them mutable using a reference to wrap the actual value. Basically, a reference is like a box, and the content inside can change.
00:13 To update the reference, we can use a column followed by an equals sign. We here refer to the name. The content of our foo changed to six.
00:22 In order to retrieve the value of a reference, we can use the carrot character. References, for example, can be used to store the state of the whole game where you are, like this.
00:49 Keep in mind to use this feature sparingly to avoid unexpected behavior. Immutability comes with lots of benefits, and you better not give them up without any good reasons.