The Function block

Make your own block · in code: Functions

What it does

Makes your own block: a small flowchart with a name, that you can run again and again with a Call block. Like Start, it begins its own flowchart, and every path under it finishes at a Return.

Use it for

Working something out the same way many times: the price with tax, a player's score, a times table.
Splitting a big program into small parts with good names.

What to fill in

Function name: What to call it, like addTax. A Call block runs it by this name.
Values it's given: Names for the values a Call gives it, separated by commas, like price, rate. Leave it empty if it needs none.
Belongs to class: Leave it empty for a plain function. Fill in a class, like Pet, to make a method: inside it, this is the object it runs on.

Try it

Open it in the editor, press Run, then change it and run it again.

Example · FunctionsPrice MachineBuild a lineTotal(price, qty) function once, then use it for pens and for notebooks.

Try it

1def lineTotal(price, qty):2    cost = price * qty3    return cost4
5
6print("Stationery shop: pens ₹10 each, notebooks ₹45 each")7pens = int(input("How many pens? "))8pensCost = lineTotal(10, pens)9books = int(input("How many notebooks? "))10booksCost = lineTotal(45, books)11total = pensCost + booksCost12print("Pens: ₹" + str(pensCost))13print("Notebooks: ₹" + str(booksCost))14print("Total to pay: ₹" + str(total))

Tips

Inside a function, the only values it knows are the ones it's given and the ones it makes itself. That keeps it separate from the rest of your program.
Each Call gets fresh values, so price inside the function never mixes up a price in the main program.
View Code turns it into a real function: function in JavaScript, def in Python, a method in Java and C#.

See it in use

Examples with the Function block

Learn it in lesson 8Functions: name a job, use it again

Goes with

Call Return