# Indexing

TODO: ADD MORE

- the "rows" and "columns" of this exercise need to be retrieved from a list of lists via index [matrix](../exercise-concepts/matrix.md)
- for iterables, individual items can be accessed with `stringname[x]` notation. Negative numbers start to count backwards [phone-number](../exercise-concepts/phone-number.md)
- finding a value by key in a dictionary using `<dictionary name>[<key name>]` The example uses passed in move arguments as `keys` to look up corresponding `values` (_method names_) for moving the robot in the _instructions_ dictionary. [robot-simulator](../exercise-concepts/robot-simulator.md)
