Count line

Count total, code, comment, and blank lines with a rough comment percentage.

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ToolLine Counter
Input
Output
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Preview

How it works

Input is split into lines, blanks are counted, supported comment-only markers are recognized, and remaining nonblank lines are treated as code. Inline markers follow the selected language’s line-based rules.

  • The report exposes several size measures rather than one LOC definition.
  • Line scanning is a quick estimate, not a language parser.

Worked example

Count lines in JavaScript
Analyze code, comment, and blank line ratios
Input
											// Setup
const app = express();

// Routes
app.get('/', handler);
app.listen(3000);
Output
												Line Count Analysis
-------------------
Total lines:   6
Code lines:    3 (50%)
Comment lines: 2 (33%)
Blank lines:   1 (17%)

When to use this

Code reviews, classroom metrics, and repository size audits count lines.

Edge cases

  • // inside a multiline string can look like a comment.
  • Code with an inline comment is not a comment-only line.
  • Marker choice changes counts for #, --, and // languages.