Course of Raku / Advanced / Containers / Special and dynamic variables 🆕 / Exercises / The topic variable

Solution: The topic variable

Here is a possible solution to the task.

Code

for 'apple', 'fig', 'cherry' {
    say "$_ has {.chars} letters";
}

🦋 You can find the source code in the file topic-variable.raku.

Output

apple has 5 letters
fig has 3 letters
cherry has 6 letters

Comments

  1. A for loop sets the topic variable $_ to each item in turn, so the block runs three times, with $_ equal to 'apple', then 'fig', then 'cherry'.

  2. Inside the string, $_ interpolates the current word, and the leading-dot .chars call — short for $_.chars — gives its length. Both refer to the same topic, which is why the count always matches the word on the line.

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