LESSON 379 OF 414 · PROJECTS: COMMAND-LINE TOOLS

CLI Tool: head v3 — Cap n at lines.length in Scala

Practice

Same signature as v2, but now n may be larger than the number of lines. If n > lines.length simply return all the lines (don't crash, don't pad). For this version assume n ≥ 0. If n is 0, or there are no lines, the result is the empty string.

Function signature:

def head(lines: Array[String], n: Int): String

Example:

Input: lines = ["alpha", "beta", "gamma"], n = 10

Output: "alpha\nbeta\ngamma"

When printed:
alpha
beta
gamma

Compute a capped end with math.min(n, lines.length) so you only take the safe prefix, then join it with newlines.

val end = math.min(n, lines.length)
return lines.slice(0, end).mkString("\n")

The full solution:

class Solution {
    def head(lines: Array[String], n: Int): String = {
        val end = math.min(n, lines.length)
        return lines.slice(0, end).mkString("\n")
    }
}

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CLI Tool: head v3 — Cap n at lines.length in Scala

Head V3 in Scala