Practice — Change, predict, fix

Use these after Lesson 1–Lesson 3. Run each program in the Playground or with elang.

This page is practice, not reference.

Change it

1. Greeting

say("Hello, Echo!");

Task: Change the message to greet a friend.

2. Variable

name: str = "Echo";
say(name);

Task: Change the value so the program prints your name.

3. Decision

temp: int = 20;

if temp >= 25 {
    say("Warm");
} else {
    say("Cool");
}

Task: Change temp so the program prints Warm.

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Predict it

Do not run these until you write your guess.

4.

n: int = 2;
say(n + 3);

Answer

5

5.

flag: bool = false;

if flag {
    say("yes");
} else {
    say("no");
}

Answer

no

6.

i: int = 1;

while i <= 2 {
    say(i);
    i = i + 1;
}

Answer

1
2

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Fix it

7. Missing semicolon

say("Hello, Echo!")

Task: Make it run. Hint: instructions end with ;.

Fixed

say("Hello, Echo!");

8. Missing type on first use

count = 1;
say(count);

Task: Declare count properly.

Fixed

count: int = 1;
say(count);

9. Missing braces

if true
    say("ok");

Fixed

if true {
    say("ok");
}

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