Week 10: Functions

A function is a piece of code that you give a name and call whenever you need it. In C, a function definition has a return type, a name, a list of parameters and a body. The parameters sit inside parentheses and are separated by commas. This week you practice typing (, ) and , on the US English layout, and you write a small function from start to finish.

What you will learn

On the US English layout:

• (: the 9 key with Shift. Press Shift with the opposite pinky, and press 9 with your right ring finger.
• ): the 0 key with Shift. Press Shift with the opposite pinky, and press 0 with your right pinky.
• ,: the , key, with your right middle finger.

A function that adds two numbers:

int add(int a, int b) {
    return a + b;
}

Technique tips

• Do not try to type the whole function in one rush. Finish the line int add( first, then add the parameters, and write the body last.
• Put a space after each comma in the parameter list. The space makes it easy to see where one parameter ends.
• After you press the comma key with your right middle finger, return that finger to the home row.
• Check the screen. Count the opening and closing parentheses on the first line before you go on.

Lessons

1. Lesson 1, learn (10 to 15 minutes): Watch the (, ) and , keys on the keyboard demo. Type each symbol five times.
2. Lesson 2, practice (10 to 15 minutes): Type the line int add(int a, int b) and the body from the example. Check each comma in the parameter list.
3. Lesson 3, review (10 to 15 minutes): Take the two-minute test with function lines. Save your result and practice the lines where you slowed down.

This week’s goal

This week’s target is 19 WPM and 93% accuracy. Finishing the week’s lessons earns you 1 star. Reach 93% accuracy for 2 stars, and also reach 19 WPM for 3 stars. One missing parenthesis in the first line causes errors in the lines below it, so keep accuracy first.