LESSON 375 OF 410 · PROJECTS: COMMAND-LINE TOOLS

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

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:

head(lines, n)

Example:

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

Output: "alpha\nbeta\ngamma"

When printed:
alpha
beta
gamma

JavaScript's slice already handles the over-cap case. lines.slice(0, n) with n bigger than lines.length just returns all elements — no extra logic needed.

The full solution is identical to v2:

class Solution {
    head(lines, n) {
        return lines.slice(0, n).join("\n");
    }
}

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

Head V3 in JavaScript