---
title: Use isEmpty instead of comparing length to zero
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > Code Security > Static Code Analysis (SAST) > SAST
  Rules > Use isEmpty instead of comparing length to zero
---

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# Use isEmpty instead of comparing length to zero

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## Metadata{% #metadata %}

**ID:** `dart-code-quality/prefer-is-empty`

**Language:** Dart

**Severity:** Notice

**Category:** Code Style

## Description{% #description %}

Comparing a collection's .length to zero (e.g. list.length == 0) is less readable and may be slower than calling .isEmpty or .isNotEmpty directly. Use .isEmpty when checking for zero length and .isNotEmpty when checking for non-zero length.

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

```dart
void main() {
  var list = [];
  if (list.length == 0) {}
  if (list.length != 0) {}
  if (list.length > 0) {}
  if (0 == list.length) {}
  if (0 != list.length) {}
}
```

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

```dart
void main() {
  var list = [];
  if (list.isEmpty) {}
  if (list.isNotEmpty) {}
  if (list.length == 1) {}
  if (list.length > 1) {}
}
```
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