Week 9: Loops

A loop repeats the same work as many times as you need. In C, a for loop has three parts: a starting value, a condition that must stay true, and a step that runs after each round. The loop below starts i at 0 and keeps going while i is less than 5, so it runs five times. This week you learn to type +, =, < and ; on the US English layout.

What you will learn

On the US English layout:

• +: the = key with Shift. Press Shift with the opposite pinky, and press the = key with your right pinky.
• =: the = key, with your right pinky.
• <: the , key with Shift. Press Shift with the opposite pinky, and press the , key with your right middle finger.
• ;: the ; key, with your right pinky.

A loop to type out:

for (int i = 0; i < 5; i++) {
    printf("hello");
}

Technique tips

• The step i++ uses the plus sign twice. Type the first plus, then finish the second one before you move on.
• Think of the opening parenthesis and the opening brace as a pair. The loop body ends with a } that you must not forget.
• Each part of the for line is separated by a semicolon. Check that you typed two of them inside the parentheses.
• Press Enter and the line inside the loop is indented for you. Do not add spaces by hand.

Lessons

1. Lesson 1, learn (10 to 15 minutes): Watch the four symbols on the keyboard demo. Type each one five times, and keep Shift timing in mind.
2. Lesson 2, practice (10 to 15 minutes): Type short loop lines such as for (int i = 0; i < 3; i++). Check that every line has three semicolons inside its parentheses.
3. Lesson 3, review (10 to 15 minutes): Take the two-minute test with loop lines. Save your result and practice the symbols you missed.

This week’s goal

This week’s target is 18 WPM and 92% accuracy. Finishing the week’s lessons earns you 1 star. Reach 92% accuracy for 2 stars, and also reach 18 WPM for 3 stars. A missing semicolon stops the loop line from working, so accuracy comes first.