---
id: javascript-error-object
title: "JavaScript Error Object"
category: "Frontend"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["Error object", "error reference", "err.name", "err.message", "error names"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.87
created_at: 2026-06-23
updated_at: 2026-06-23
review_reason: ""
merge_history: []
tags: ["javascript", "js", "web", "frontend", "w3schools", "errors", "error-object"]
raw_sources: ["https://www.w3schools.com/js/js_error_object.asp"]
applied_in: []
github_commit: ""
---

# [[JavaScript Error Object]]

## 🎯 한 줄 통찰 (One-line insight)
JavaScript's built-in Error object carries information when an error occurs, exposing useful properties such as `name` and `message`, with `name` returning one of six standard error types. [S1]

## 🧠 핵심 개념 (Core concepts)
- **The Error object** is built in and provides information when errors occur, with useful properties like `name` and `message`. [S1]
- **`Error.isError(x)`** returns true if a value is an Error. [S1]
- **Six error names** — the `name` property can return `EvalError`, `RangeError`, `ReferenceError`, `SyntaxError`, `TypeError`, or `URIError`. [S1]
- **EvalError is deprecated** — use `SyntaxError` instead. [S1]
- **Avoid non-standard members** — several properties and methods are browser-specific or outdated and should not be used. [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **Read `name` to branch on error type** — the standardized set of six error names lets handling code distinguish what went wrong. [S1]
- **Stick to standard members** — rely on `name`, `message`, and `cause`; avoid deprecated/non-standard properties and methods. [S1]

## 📖 세부 내용 (Details)
**The Error Object**
JavaScript includes a built-in error object providing information when errors occur, with useful properties like `name` and `message`. [S1]

**Error Object Methods & Properties** [S1]

| Property / Method | Description |
|-------------------|-------------|
| `new Error()` | Creates a new Error object |
| `name` | Sets or returns an error name |
| `message` | Sets or returns an error message |
| `cause` | Sets or returns an error cause |
| `Error.isError(x)` | Returns true if a value (x) is an Error |

**Error Names**
The `name` property can return one of six error types: [S1]

| Error Name | Description |
|------------|-------------|
| `EvalError` | Deprecated - use SyntaxError instead |
| `RangeError` | A number "out of range" has occurred |
| `ReferenceError` | An illegal reference has occurred |
| `SyntaxError` | A syntax error has occurred |
| `TypeError` | A type error has occurred |
| `URIError` | An error in encodeURI() has occurred |

Each error name has an associated "Try it" button linking to examples. No inline code examples are displayed on this reference page. [S1]

**Non-Standard Properties and Methods**
The page warns against using deprecated, browser-specific, or outdated members: [S1]
- **Properties:** `arguments`, `caller`, `columnNumber`, `description`, `displayName`, `fileName`, `lineNumber`, `number`, `stack`
- **Methods:** `evalError()`, `internalError()`, `toSource()`

## 🛠️ 적용 사례 (Applied in summary)
This is a reference page; the source displays no inline code examples (only "Try it" links). The applicable usage is reading `err.name` / `err.message` inside a `catch` block, as shown on the related Error Statements page. No external project/commit applications found in the source.

## 💻 코드 패턴 (Code patterns)
Not found in source as displayed inline code; the reference page exposes only the property/method and error-name tables above and links to external "Try it" examples. The canonical access pattern (drawn from the same family of pages) is reading the standard properties:
```javascript
try {
  // ...
} catch(err) {
  let name = err.name;       // e.g. "TypeError"
  let message = err.message; // human-readable description
}
```

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- **EvalError deprecation** — the source marks `EvalError` as deprecated in favor of `SyntaxError`. [S1]
- **Non-standard members** — listed properties/methods are flagged as browser-specific or outdated and should be avoided. [S1]

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual (실제 적용 사례 발견 시 applied/validated로 승격 가능)
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.87
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[JavaScript Tutorial]]
- **관련 개념:** [[JavaScript Errors Intro]], [[JavaScript Error Statements]], [[JavaScript Silent Errors]], [[JavaScript Debugging]]
- **참조 맥락:** The reference for the object received in a `catch` block and the standardized error names used to identify failures.

## 📚 출처 (Sources)
- [S1] W3Schools — JavaScript Error Object — https://www.w3schools.com/js/js_error_object.asp

## 📝 변경 이력 (Change history)
- 2026-06-23: Initial draft synthesized from the W3Schools "JavaScript Error Object" page (Astra wiki-curation, P-Reinforce v3.1 format).