Notes on software and the ideas behind it

Find the meaning
behind the code.

I’m Fred Yang. I write about software—how it works, why it behaves the way it does, and the ideas that make code easier to reason about.

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Working notes / 2026

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Architecture, reactivity, and the hidden relationships that shape frontend systems.

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Part 1 Angular Change Detection, what is the end game?

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Observable with async pipe used multiple times in Angular template

There is a question in stackoverlfow Angular - Observable with async pipe used multiple times in template… Good Practice or Bad?
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Demystifying the syntax of structural directive

Structural directive is a special directive. Angular comes with a couple of them such as ngIf, ngFor. Angular provides detailed documentation about the structural directive. There are two syntaxes to use a directive, the...
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Hello Jekyll!

I haven’t written any blog for 3 years, because the blogger platform does not provide markdown support. Now that I have migrated it to Jekyll, and let’s blog!
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javascript

Array(n) constructor

JavaScript Array constructor can be used in the follow syntax. const items1 = new Array(2); //(2) [empty × 2] //or const items2 = Array(2); //(2) [empty × 2]
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