Demo Identify How to Assign Issues

In this lesson you’ll learn how to assign GitHub issues to collaborators, add and manage labels to categorize work, notify teammates, and avoid a common JavaScript bug that can occur when cloning items by mutating an array during iteration. Scenario

Alice assigned the repository owner, Siddharth Barahalikar, to this issue because he owns the repository and is the most appropriate reviewer.
The issue references a problematic code snippet that causes unexpected behavior when adding cloned items to an array while iterating over it.

Problematic code example

// script.js
case 'multiBall':
    if (gameState.balls.length < 5) { // This check is insufficient
        gameState.balls.forEach(ball => {
            gameState.balls.push({...ball});
        });
    }

Why this is a problem

Mutating an array while iterating over it (pushing into the same array inside forEach) can produce unexpected duplication or effectively run indefinitely in some circumstances.
The guard gameState.balls.length < 5 is insufficient because the loop itself increases the array length as it runs, invalidating the original check.

How to fix it

Iterate over a shallow copy of the array so the list you’re iterating doesn’t change while you push new items.
Or build a new array of clones and assign it back (using concat / spread) to avoid in-loop mutation.
Always enforce a maximum (e.g., MAX_BALLS) and compute how many clones you actually need so you don’t exceed limits.

Example 1 — iterate over a copy

// script.js
case 'multiBall': {
  const MAX_BALLS = 5;
  if (gameState.balls.length < MAX_BALLS) {
    // Only clone as many as needed to avoid exceeding MAX_BALLS
    const clonesNeeded = Math.min(gameState.balls.length, MAX_BALLS - gameState.balls.length);
    const existingBalls = gameState.balls.slice(0, clonesNeeded); // copy the items we will clone
    existingBalls.forEach(ball => {
      gameState.balls.push({ ...ball });
    });
  }
  break;
}

Example 2 — create a new array with concat/map

// script.js
case 'multiBall': {
  const MAX_BALLS = 5;
  if (gameState.balls.length < MAX_BALLS) {
    const clonesNeeded = Math.min(gameState.balls.length, MAX_BALLS - gameState.balls.length);
    const clones = gameState.balls.slice(0, clonesNeeded).map(ball => ({ ...ball }));
    gameState.balls = gameState.balls.concat(clones);
  }
  break;
}

Avoid mutating the same array while iterating. Use a copy or build a new array to preserve predictable behavior and respect your maximum limits.

Assigning issues to collaborators

Repository owners and users with write access can assign issues to themselves or other collaborators.
If someone else is better suited to fix the issue, search for their username in the assignee picker and add them as an assignee.
Assigned users receive GitHub notifications and will see the issue in their notifications feed.

Adding labels to categorize issues

Labels help triage and prioritize work (e.g., bug, enhancement, documentation, high-priority).
You can use the repository’s default labels or create custom labels to suit your workflow.
Newly-created labels can take a few seconds to appear in the label picker.

It’s going to show you all the default nine labels available for this repository.

The image shows a GitHub repository's "Labels" section with a list of nine labels, each associated with a description, such as "bug," "documentation," and "enhancement."

Creating a new label

Click “New label”.
Enter a name, add a description, and pick a color.
Example: create a high-priority label with description “Must be fixed ASAP”.

The image shows a GitHub interface where a user is creating a new issue label called "high-priority" with the description "Must be fixed ASAP" and a color selection being made.

After creating the label, add it to the issue (for example, add bug and high-priority). It may take a couple of seconds for a newly-created label to appear in the picker. Once labels and assignees are set, assigned people should receive notifications in their GitHub notifications feed.

The image is a screenshot of a GitHub notifications page showing various issues and security advisories from different repositories. It includes a list of unread notifications, categorized by assignments, mentions, and security alerts.

Commenting and mentioning users

Use comments to add context, request reviews, or propose fixes on an issue.
Use @username in a comment to mention someone and trigger a notification so they can respond.

Example comment

@SiddharthBarahalikar Can you take a look at the multiBall logic? It duplicates balls by mutating the array while iterating.

Quick reference table

Action	Purpose	Example
Assign an issue	Route responsibility to a collaborator	Use the assignee picker, select a teammate
Add labels	Categorize and prioritize work	Add `bug`, `enhancement`, or `high-priority`
Mention a user	Notify someone about an issue or comment	`@SiddharthBarahalikar` in a comment

Summary

Assign issues to the person best suited to resolve them; assignees receive notifications.
Use labels to triage, filter, and prioritize issues; custom labels help reflect team workflows.
Do not mutate an array while iterating over it — iterate over a copy or build a new array to add cloned items safely.

Links and references

Watch Video

Demo Describe How to Create an Issue

Demo Describe How to Pin an Issue

Introduction

Git and GitHub Basics

GitHub Entities

GitHub Markdown

GitHub Desktop

GitHub Mobile

GitHub Repositories

Issues

Pull Requests

Discussions

Notifications

Gists, Wikis, and GitHub Pages

GitHub Actions

GitHub Copilot

GitHub Codespaces

Manage Your Work with GitHub Projects

Authentication and Security

GitHub Administration

Benefits of Open-Source Community

Benefits of Open Source – Applications

Demo Identify How to Assign Issues

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