Array: A collection of similar data of a fixed length. E.g. myArray = ["Apple", "Banana", "Cherry"]
List: A collection of different data types of any size. E.g. myList = ["Apple", "B" , 3.142, ]
Data Structure: A storage that is used to store and organize data (such as Arrays)
One-dimentional Array: An array that holds a "row" of data
two-dimentional Array: An array that holds a "rows" and "columns" of data
An array can be created like this:
arrayName = [ "Value 1", "Value 2" , .... ]
Look at the image on the left.
What would you think the code below will do:
print ( a [0] )
Look at the code for each question.
What do you think will be the output?
What is the actual output?
What is the output:
myArray = ["Apple", "Banana", "Cherry"]
print (myArray)
Look at the code on the right.
Run it and see what it does.
Click on the pencil icon at the top to see the code again.
FIRST EXAMPLE:
Run the program and see what it does
Add some items into myShoppingList = [], so that it already starts with items.
What does while removeItem != "": do? How does this stop?
Look at this code for items in myShoppingList: What is different about this for loop?
Help:
print ( ) is used to output text
input( ) is used to get the user to type something
Variables store values that can change.
Name = Value here
To manipulate "Strings":
len( word ) returns how long it is
.upper() turns it to upper case
.lower() turns it to lower case
variable[x] returns the letter at position x
int( string) turns it to a string (if possible)
float (string) turns it to a float (if possible)
str (variable) turns it to a string " "
Boolean: a data type that can hold one of two values (true or false)
> Symbol: Greater than
< Symbol: Less than
== Symbol: Compares if both values are the same
!= Symbol: Not equal to
>= Symbol: Greater than or equal to
<= Symbol: Less than or equal to
Selection -
if (condition) :
(indent) program here....
Iteration -
for varName in range (start, end, increment):
(indent) program here....
while (condition) :
program here ....
Lists:
myList = [ "item1", "item2", "item3"]
print (myList)
print (myList[0]) #Outputs 1st item
myList.append("Item4") #Add new item
myList.remove("Item4") #Removes "item4"
myList[0] = "newItem" #Changes value in 0
Create a program to store these values in one list:
1,1,2,3,5,8,12,20
then print it all out
Create a program with this list:
myList = [ "item1", "item2", "item3"]
remove "item1" then print the list.
Create a program with this list:
myList = [ "item1", "item2", "item3"]
change the value of item2 to your favourite food using this code:
myList[1] = "food here"
print the whole list.
Create a program that stores peoples name for a volunteering group.
Keep adding names into the list until a blank value "" is added.
Output the whole list
An array can be created like this:
arrayName = [ "Value 1", "Value 2" , .... ]
Look at the image on the left.
What would you think the code below will do:
print ( a [1] )
An array can be created like this:
arrayName = [ "Value 1", "Value 2" , .... ]
Look at the image on the left.
What would you think the code below will do:
print ( a [4] )
What is the output:
myArray = ["Apple", "Banana", "Cherry"]
print (myArray[0])
What is the output?
myArray = []
myArray.append("A")
print (myArray)
What is the output?
cars = ["Ford", "Volvo", "BMW"]
cars.remove("Ford")
print(cars)
What is the output?
cars = ["Ford", "Volvo", "BMW"]
cars.remove("Ford")
print(cars[0])