/**
* Groups words by their first letter.
*
* @param words List of words to group
* @return Map where each key is a first letter, and each value is a list of words
*/
fun groupByFirstLetter(words: List<String>): Map<Char, List<String>> {
// groupBy automatically creates a map: key -> list of items
// { it.first() } extracts the first character of each word
return words.groupBy { it.first() }
}
fun main() {
// List of words to group
val words = listOf(
"Python", "JavaScript", "C", "Java", "C#", "PHP",
"C++", "Pascal", "SQL", "Rust"
)
val grouped = groupByFirstLetter(words)
// Print each group
for ((letter, group) in grouped) {
println("$letter: ${group.joinToString(prefix = "[", postfix = "]")}")
}
// Print the entire map
println(grouped)
}
/*
run:
P: [Python, PHP, Pascal]
J: [JavaScript, Java]
C: [C, C#, C++]
S: [SQL]
R: [Rust]
{P=[Python, PHP, Pascal], J=[JavaScript, Java], C=[C, C#, C++], S=[SQL], R=[Rust]}
*/
