Constructors, Methods, and Class Fields

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Lesson format7 sections1 code block1 practice itemUpdated Aug 23, 2026

#This example demonstrates constructors, methods, and class fields directly. Change one input at a time and observe the result; the goal is to connect the syntax to the runtime behavior rather than treating the snippet as a recipe.#link

Observation	Diagnostic question
Runtime value	What value actually arrived?
Language rule	Which rule determines the result?

javascript

function User(name) {
  this.name = name;
}
User.prototype.greet = function () {
  return `Hi ${this.name}`;
};
console.log(new User('Omar').greet());

Live JavaScript preview

Keep the experiment focused on constructors, methods, and class fields and change one assumption at a time.

info

Keep the experiment focused on constructors, methods, and class fields and change one assumption at a time.

★ 20 XP

exercise BLOCK (★ 20 XP)

Which statement best matches the behavior taught in “Constructors, Methods, and Class Fields”?

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This example demonstrates constructors, methods, and class fields directly. Change one input at a time and observe the result; the goal is to connect the syntax to the runtime behavior rather than treating the snippet as a recipe.

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Last updated

August 23, 2026

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curl -H "Accept: text/markdown" "https://vulnarex.com/api/content/lessons?courseSlug=complete-javascript-course&lessonSlug=constructors-methods-and-class-fields&lang=en&format=markdown"

MCP Server Config (mcp.json)

{
  "mcpServers": {
    "vulnarex": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-fetch"],
      "env": { "MCP_FETCH_URL": "https://vulnarex.com" }
    }
  }
}

MCP Server Card/.well-known/mcp.json A2A Agent Card/.well-known/agent-card.json API Catalog/.well-known/api-catalog robots.txt/robots.txt

Laboratory sanity code

Isolate active probes on matched virtual networks and keep execution streams sandboxed.

Observation

Diagnostic question

Runtime value

What value actually arrived?

Language rule

Which rule determines the result?