dotnet/runtime

Prefer Dictionary.Remove(key, out value) over Dictionary.this[key], followed by Dictionary.Remove(key)

Open

#33,800 opened on Mar 19, 2020

View on GitHub
 (7 comments) (0 reactions) (0 assignees)C# (5,445 forks)batch import
api-approvedarea-System.Collectionscode-analyzercode-fixerenhancementhelp wanted

Repository metrics

Stars
 (17,886 stars)
PR merge metrics
 (Avg merge 12d 11h) (661 merged PRs in 30d)

Description

Dictionary.ContainsKey<K, V(key), followed by Dictionary<K, V.this[key], followed by Dictionary<K, V>.Remove(key) can be combined into a single Remove call, using the overload accepting out TValue value.

Category: Performance

Contributor guide

Research direction
Identify usages of the pattern `if (dict.ContainsKey(key)) { var v = dict[key]; dict.Remove(key); ... }` and replace with `if (dict.Remove(key, out var v)) { ... }`.
Tech stack
csharp
Domain
backend
Issue type
Performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C#.NET
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75