Creating a new Angular project - Performance Optimization Steps

Performance: Creating a new Angular project

MEDIUM IMPACT

This affects the initial page load speed and bundle size of the Angular app.

Setting up a new Angular project for fast loading

Angular

ng new my-app --standalone --skip-install=true

Creates a minimal project without routing or extra styles, reducing bundle size and dependencies.

📈 Performance GainSaves 150kb+ in bundle size, improves LCP by 200-400ms

Setting up a new Angular project for fast loading

Angular

ng new my-app --routing --style=scss --strict=false --skip-install=false

Includes routing and SCSS by default, adds more dependencies and larger initial bundle size.

📉 Performance CostAdds 200kb+ to initial bundle, increases LCP by 300-500ms on slow networks

Performance Comparison

Pattern	DOM Operations	Reflows	Paint Cost	Verdict
Default Angular new project with routing and SCSS	Moderate DOM nodes	Multiple reflows during initial render	High paint cost due to styles and components	[X] Bad
Minimal Angular new project without routing or extra styles	Minimal DOM nodes	Single reflow on initial render	Lower paint cost with fewer styles	[OK] Good

Rendering Pipeline

Creating a new Angular project sets the base code and dependencies that affect how the browser loads, parses, and renders the app.

→Network

→Parse & Compile

→Style Calculation

→Layout

→Paint

⚠️ BottleneckNetwork and Parse & Compile stages due to large initial bundle size

Core Web Vital Affected

LCP

This affects the initial page load speed and bundle size of the Angular app.

Optimization Tips

1Start Angular projects with --standalone to reduce initial bundle size.

2Avoid adding routing or extra styles unless needed at start.

3Use DevTools Network and Performance panels to monitor load and render times.

Performance Quiz - 3 Questions

Which Angular new project option helps reduce initial bundle size?

A Including SCSS styles

B Using --standalone flag

C Adding routing by default

D Enabling strict mode

DevTools: Network and Performance panels

How to check: Open DevTools, go to Network tab, reload page and check bundle size and load time. Then use Performance tab to record page load and check scripting and rendering times.

What to look for: Look for large initial JS bundle sizes and long scripting times that delay LCP.

Practice

1. What command do you use to create a new Angular project named my-app with default settings?

easy

A. ng generate project my-app

B. ng create my-app

C. angular new my-app

D. ng new my-app

Solution

1. Step 1: Understand Angular CLI command for new projects

   The Angular CLI uses ng new followed by the project name to create a new project.

2. Step 2: Identify the correct syntax

   The correct command is ng new my-app. Other options are invalid CLI commands.

3. Final Answer:

   ng new my-app -> Option D

4. Quick Check:

   Angular CLI new project = ng new [OK]

Hint: Use 'ng new' plus project name to create Angular app [OK]

Common Mistakes:

• Using 'ng create' instead of 'ng new'
• Typing 'angular new' which is not a CLI command
• Using 'ng generate project' which is invalid

2. Which of the following commands correctly creates a new Angular project with routing enabled and SCSS as the style format?

easy

A. ng new my-app --routing --style=scss

B. ng new my-app -routing -style=scss

C. ng new my-app --routing scss

D. ng new my-app --route --style=scss

Solution

1. Step 1: Recall Angular CLI options for routing and style

   The correct flags are --routing to enable routing and --style=scss to set SCSS styles.

2. Step 2: Check syntax correctness

   ng new my-app --routing --style=scss uses correct double dashes and equals sign. Other options have wrong flags or missing dashes.

3. Final Answer:

   ng new my-app --routing --style=scss -> Option A

4. Quick Check:

   Enable routing and SCSS with --routing and --style=scss [OK]

Hint: Use double dashes and equals for options in ng new [OK]

Common Mistakes:

• Using single dash for long options
• Writing '--route' instead of '--routing'
• Omitting equals sign for style option

3. After running ng new test-app --routing --style=css and then cd test-app followed by ng serve, what will happen?

medium

A. The app will fail to compile due to missing routing module

B. The Angular app will compile and be available at http://localhost:4200

C. The app will compile but show a blank page because CSS is not supported

D. The command will throw an error because 'ng serve' must be run before 'cd test-app'

Solution

1. Step 1: Understand Angular CLI workflow

   Creating a project with routing and CSS style is valid. Changing directory into the project folder is required before serving.

2. Step 2: What ng serve does

   ng serve compiles and launches a local server at port 4200 by default, showing the app in the browser.

3. Final Answer:

   The Angular app will compile and be available at http://localhost:4200 -> Option B

4. Quick Check:

   ng serve runs app at localhost:4200 [OK]

Hint: Run ng serve inside project folder to view app in browser [OK]

Common Mistakes:

• Running ng serve outside project folder
• Assuming CSS is unsupported
• Expecting errors from valid routing option

4. You run ng new my-app --routing --style=less but get an error saying the style option is invalid. What is the likely cause?

medium

A. LESS is not supported by Angular CLI by default without extra setup

B. The --routing flag must come after --style option

C. You must use --styles instead of --style

D. The project name 'my-app' is invalid

Solution

1. Step 1: Check Angular CLI supported style formats

   Angular CLI supports CSS, SCSS, Sass, and Stylus by default. LESS requires extra setup or dependencies.

2. Step 2: Analyze error cause

   The error about invalid style option likely means LESS is not recognized without additional configuration.

3. Final Answer:

   LESS is not supported by Angular CLI by default without extra setup -> Option A

4. Quick Check:

   LESS needs extra setup, not default [OK]

Hint: Check if style format is supported by default before using [OK]

Common Mistakes:

• Thinking option order matters
• Using --styles instead of --style
• Assuming project name causes style errors

5. You want to create a new Angular project named shop-app with routing enabled, SCSS styles, and skip installing npm packages initially. Which command should you use?

hard

A. ng new shop-app --routing --style=scss --skipNpm

B. ng new shop-app --routing --style=scss --no-install

C. ng new shop-app --routing --style=scss --skip-install

D. ng new shop-app --routing --style=scss --skip-npm

Solution

1. Step 1: Identify correct flags for skipping npm install

   The Angular CLI uses --skip-install to skip installing npm packages after project creation.

2. Step 2: Confirm routing and style flags

   --routing enables routing, and --style=scss sets SCSS styles correctly.

3. Final Answer:

   ng new shop-app --routing --style=scss --skip-install -> Option C

4. Quick Check:

   Use --skip-install to skip npm install [OK]

Hint: Use --skip-install to avoid automatic npm install [OK]

Common Mistakes:

• Using incorrect flag names like --no-install
• Trying camelCase flags like --skipNpm
• Using hyphenated flags not recognized by CLI