Lab 3.04 - Aliasing & Scope

Aliasing

Will updating b affect a? Explain why or why not?
```
      a = [1, 2, 4]
      b = a
```

Predict what my_list list will print out when this code is run. If you are not sure check the code by copying and running it.

   # input: a list of ints
   # output: an int
   def update_list(a_list): 
       if len(a_list) > 5: 
           a_list[3] = "yo"
           b = a_list[4]
          c = b
          c = 100
   my_list = [1, 2, 3, 4, 5]
   update_list(my_list)

Scope

Draw a stack diagram for the following:

  var_1 = "kittens"
  var_2 = "cookies"

  # input: a string
  # output: a string
  def my_function(my_favorite_things): 
      song_lyrics = "rain drops on roses,"
      combined_song = song_lyrics + my_favorite_things
      return combined_song

  # input: a string
  # output: a string    
  def my_function_2(item, item2): 
      full_lyrics = item + "on " + item2
      full_song = my_function(full_lyrics)
      return full_song

  my_song = my_function_2(var_1, var_2)

Write down what (if anything) is wrong with the following code. If there was an issue write out how to fix it. If you are unsure copy and run the code and fix it.
```python var_1 = 'cat' var_2 = 'dog'

def print_out_my_favorite(favorite_pet): if favorite_pet == var_1: print("My favorite pet is the cat.") if favorite_pet == var_2: print("My favorite pet is the dog.") var_2 = "cat"

print_out_my_favorite(var_1) print(var_2)

2. ```python
var_1 = 'cat'
var_2 = 'dog'

def print_out_my_favorite(favorite_pet): 
    var_1 = 'dog'
    var_2 = 'cat'
    if favorite_pet == var_1:
        print("My favorite pet is the cat.")
    if favorite_pet == var_2: 
        print("My favorite pet is the dog.")

print_out_my_favorite(var_1)
print(var_1 + " " + var_2)

```python var_1 = 'cat' var_2 = 'dog'

def print_out_my_favorite(favorite_pet): if favorite_pet == var_1: print("My favorite pet is the cat.") if favorite_pet == var_2: print("My favorite pet is the dog.")

print_out_my_favorite(var_1) print(var_2) ```

Write a program that has a global variable, my_num. Create three functions that update my_num:
1. add2: this function adds 2 to my_num
2. multiply_num: this function takes in a parameter, multiplier, and multiplies my_num by that parameter
3. add2_and_multiply: this function takes in a parameter, multiplier, and calls both add2 and multiply_num.