---
title: "Function that multiplies x by 2 in javascript"
query: "function that multiplies x by 2 in javascript"
url: "https://parka-d7b.pages.dev/pocket/function-multiplies-x-2-javascript"
providers: ["claude_haiku", "cohere", "deepseek", "gemini", "glm4", "gpt_oss", "grok", "hermes", "kimi", "llama", "mercury", "microsoft", "minimax", "mistral", "nemotron", "perplexity", "qwen", "tongyi"]
confidence: 89
created: "2025-12-07T00:05:52.334072+00:00"
updated: "2025-12-07T00:05:52.334072+00:00"
---

# function that multiplies x by 2 in javascript

> This content was synthesized from multiple AI providers: claude_haiku, cohere, deepseek, gemini, glm4, gpt_oss, grok, hermes, kimi, llama, mercury, microsoft, minimax, mistral, nemotron, perplexity, qwen, tongyi

---

## How to multiply a number by 2 in JavaScript

The core operation is the multiplication operator `*`.  
A function that takes a single argument `x` and returns `x * 2` is sufficient for doubling any numeric value.

### 1. Classic function declaration
```javascript
function multiplyByTwo(x) {
  return x * 2;
}
```

### 2. Arrow function (concise ES6 syntax)
```javascript
const multiplyByTwo = x => x * 2;
```

### 3. Function expression
```javascript
const multiplyByTwo = function(x) {
  return x * 2;
};
```

All three forms are equivalent; choose the style that matches your codebase.

### Example usage
```javascript
console.log(multiplyByTwo(5));   // → 10
console.log(multiplyByTwo(3.5)); // → 7
console.log(multiplyByTwo(-4));  // → -8
```

### Why it works
- The `*` operator multiplies two numbers, coercing its operands to numeric values if necessary【2】.
- JavaScript treats `2` as a numeric literal, so `x * 2` directly yields the doubled value.

### Edge considerations
- **Non‑numeric inputs**: JavaScript will attempt type coercion (`multiplyByTwo("3")` → `6`). For stricter behavior, add validation.
- **BigInt**: The operator also works with `BigInt` values【2】, e.g., `multiplyByTwo(10n)` → `20n`.

### Naming variations
Different tutorials use different function names (`multiplyByTwo`, `double`, etc.). The functionality remains identical; only the identifier changes.

---

**References**  
- Multiplication operator documentation【2】  
- Common examples of numeric multiplication in JavaScript【1】【3】

---

## About This Content

This response was synthesized by [Parka AI](https://parka-d7b.pages.dev) from multiple AI providers.
Sources include: claude_haiku, cohere, deepseek, gemini, glm4, gpt_oss, grok, hermes, kimi, llama, mercury, microsoft, minimax, mistral, nemotron, perplexity, qwen, tongyi.

For the most current information, please verify from primary sources.

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