Defining a function means to write a function with all of the code inside it.
Defining a function does not run any of the code inside that function. It only teaches the computer what that function means. You can actually run that code by “calling” the function.
Example
The way you define a function is Javascript is:
function nameOfMyFunction() {
// function body: code goes here
}
The function definition starts with the word function followed by the name of the function. At the end of the name, be sure to include the () to complete it.
All of the code for the function goes in between the { and }
That section is called the “function body.”
Defining vs. Calling
Defining a function is different from “calling a function.” When you “call” a function, you just write the name of the function followed by (); like this:
nameOfFunctionToRun();
This will actually run the code inside that function, whereas defining the function does not run the code. It just defines the name.
Teaching Karel a New Word
In Karel, you can think of defining a function as teaching Karel a new word.
You can teach Karel any new word you want using and of the other words that Karel already know, including other words you have taught Karel.