Free · Count names used in JavaScript

JavaScript Identifier Frequency

Count identifier names and show their frequency, first line, and example role.

Real Acorn 8.18 parser
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Count JavaScript identifiers

Paste JavaScript, choose module or script mode, and let Acorn inspect the syntax without running the code.

Add JavaScriptThe code is parsed, never run

JavaScript source 1,028 / 120,000 characters

import { formatPrice } from "./money.js";
export const storeName = "Little Leaf Market";

const products = [
  { id: 1, name: "Garden Tote", price: 3499, tags: ["gift", "summer"] },
  { id: 2, name: "Seed Pack", price: 999, tags: ["garden"] },
];

class Cart {
  constructor(items = []) {
    this.items = items;
  }

async total() {
    const prices = await Promise.resolve(this.items.map((item) => item.price));
    return prices.reduce((sum, price) => sum + price, 0);
  }
}

export async function showProducts(customer) {
  // Keep only products this customer can see.
  const visible = products.filter((product) => product.price > 0);
  for (const product of visible) {
    console.log(product.name, formatPrice(product.price));
  }

document.querySelector("#buy")?.addEventListener("click", () => {
    console.log(customer?.name ?? "Guest");
  });

if (visible.length === 0) return "No products";
  return visible.map(({ name }) => name).join(", ");
}

export const loadDetails = async () => import("./details.js");

Private syntax parsingAcorn 8.18.0 · latest ECMAScript · code is never executed

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Paste JavaScript or open a file.
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Acorn reads the JavaScript inside this browser tab and never runs it. Bookify does not upload or save the code. Input, syntax-tree depth, node count, table rows, and AST JSON all have clear limits.