Pseudocoding
Pseudocoding
- An informal high-level description
- Operating principle of a program and/or algorithm
- Uses of structural conventions of a programming language
- Intended for humans rather than machines
Pseudocoding
Explaining what your code does to a 3-year-old
What are the guidelines?
- Rule #1: No actual code allowed.
- Rule #2: Explain what you're doing in English using Software Engineering concepts.
- 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).
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
Examples
Our task: add 5 to each item in an array.
//iterate through the array
for (var i = 0; i < arr.length; i++) {
//add 5 to each item
arr[i] += 5;
}Pseudocode:
//iterate through the array
Pseudocode:
//iterate through the array
//add 5 to each item
Actual code:
You'll notice that each line of pseudocode gives us clear instructions for a task we can do
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
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
"invoke" this with the array [1,2,3,4]
(all in your head, or before coding)
This helps you spot bugs before you even write code!
Key Takeaways
- Make your life easier. Before jumping into writing code...
- break down complex problems
- write down your step-by-step plan
- Follow the 5 guidelines
- Practice being the JS interpreter and mentally execute your pseudocode with pretend inputs
Today's Exercises
These exercises are not necessarily tied to today's lecture material (though you should always use pseudocoding to solve problems!)
Practice going through your previous repos/assessments (especially ones you found difficult) and try pseudocoding your way through them.
Pseudocode
By telegraphprep
