Week 6: Brackets and braces

Square brackets [ ] select one item from an array. Curly braces { } open and close a block of code. Both come in pairs, and each pair must close in the right place, so keep them from getting mixed up. This week you learn to type [, ], { and } on the US English layout.

What you will learn

On the US English layout:

• [: the [ key, with your right pinky.
• ]: the ] key, with your right pinky.
• {: the [ key with Shift. Press Shift with the opposite pinky, and press [ with your right pinky.
• }: the ] key with Shift. Press Shift with the opposite pinky, and press ] with your right pinky.

A quick example: numbers[0] reads the first item of an array, because C counts from zero. The three lines below form an if block:

if (x > 0) {
    printf("positive");
}

Technique tips

• Think of each pair together. When you type {, keep the closing } in mind so the block has a clear end.
• Press Enter and the next line is indented for you automatically. Do not add extra spaces by hand.
• Your right pinky does most of the work here, so keep the rest of your fingers on the home row.
• Remember that counting starts at zero. In numbers[0], the 0 points to the first item.

Lessons

1. Lesson 1, learn (10 to 15 minutes): Watch the four symbols on the keyboard demo. Type each one five times, and notice how Shift changes the { and } keys.
2. Lesson 2, practice (10 to 15 minutes): Type numbers[0], numbers[1] and the if block above. Check that every opening bracket and brace has a matching close.
3. Lesson 3, review (10 to 15 minutes): Take the two-minute test with bracket and brace lines. Save your result and practice the symbols you missed.

This week’s goal

This week’s target is 15 WPM and 91% accuracy. Finishing the week’s lessons earns you 1 star. Reach 91% accuracy for 2 stars, and also reach 15 WPM for 3 stars. An unclosed brace can stop a whole program from running, so accuracy comes first.