# Source: https://docs.datadoghq.com/security/code_security/static_analysis/static_analysis_rules/typescript-common-security/unique-function-arguments.md

# Source: https://docs.datadoghq.com/security/code_security/static_analysis/static_analysis_rules/javascript-common-security/unique-function-arguments.md

---
title: Function argument names should be unique
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > Code Security > Static Code Analysis (SAST) > SAST
  Rules > Function argument names should be unique
---

# Function argument names should be unique

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## Metadata{% #metadata %}

**ID:** `javascript-common-security/unique-function-arguments`

**Language:** JavaScript

**Severity:** Warning

**Category:** Error Prone

## Description{% #description %}

A function's parameter names should all be unique. Otherwise, a latter parameter will overwrite the former parameter. This behavior can lead to unintended bugs and it difficult to debug in the future.

## Non-Compliant Code Examples{% #non-compliant-code-examples %}

```javascript
function addition(foo, bar, foo) {
  console.log(foo + bar + foo);
}

addition(1, 2, 3); // outputs 8
```

## Compliant Code Examples{% #compliant-code-examples %}

```javascript
function addition(foo, bar, baz) {
  console.log(foo + bar + baz);
}

addition(1, 2, 3); // outputs 6
```
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