Pseudocoding

Explaining what your code does to a 3-year-old

Pseudocoding Course

What's the point of pseudocoding?
What are the guidelines of pseudocoding?
When do we use pseudocoding?
Examples of pseudocode

What's the point?

Demystify complex problems
Remove the need for you to hold everything in your head
Create clarity and more definition to reduce ambiguity
Give yourself a discrete, single solvable thing to work on - focus
Explain your approach to someone else

What are the guidelines?

Rule #1: No actual code allowed.
Rule #2: Explain what you're doing in English using very simple terms.
Rule #3: Each line must be something that can be turned into code.
Rule #4: You don't need to know how that line will be turned into code yet.
Rule #5: Indent pseudocode as you would real code to show control flow (loops, conditions).

Examples

Our task: add 5 to each item in an array.

Pseudocode:

//iterate through the array

//add 5 to each item

Actual code:

//iterate through the array
for (var i = 0; i < arr.length; i++) {
  //add 5 to each item
  arr[i] += 5;
}

Examples

Create a function, checkStore, that searches through our bookStore array for a user-inputted book

Pseudocode:

//declare a function that takes a bookname string as a parameter

//iterate through the bookStore array

//find the title of each book

//check if the title matches the bookname

//if so, pop up alert box with title, author, and price

//ask the user if they want to add the item to their cart

//if the user selects yes, add to their cart

//if the book isn't found, alert the user that we don't have it

Example

You'll notice that each line of pseudocode gives us clear instructions for a task we can do.

Do we follow the guidelines?

Rule #1: No actual code allowed.
Rule #2: Explain what you're doing in English using very simple terms.
Rule #3: Each line must be something that can be turned into code.
Rule #4: You don't need to know how that line will be turned into code yet.
Rule #5: Indent pseudocode as you would real code to show control flow (loops, conditions).

When do we use it?

At the start of any problem we don't have an obvious solution to
Whenever we get stuck
In pair programming to explain our approach
When approaching any complex problem
In technical interviews, no matter what

When do we use it?

All the time.

It's super valuable.

Be The Machine

Practice "executing" your pseudocode with pretend inputs.
Just as we like stepping through our actual code line by line to explain what it's doing, we can do the same with our pseudocode.

Be the Machine

create a function that multiplies every even number in an input array by 10 and returns the modified array

//declare a function that takes an array as a parameter

//iterate through that array

//check to see if each item is even

//if so, overwrite the array at that position with that item multiplied by 10

//return the array

Let's "invoke" this with the array [1,2,3,4]

This helps you spot bugs before you even write code!