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

Recently mapped

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

jquery

jQuery object is an array like object

jQuery object is not an Array object, but it looks like an array. The following code how this is implemented? var o = {"0":1, "1": 2, length:2}; var a = [].slice.call(o, 0); alert(a); //...
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javascript

object toString

The memeber toString of different object is redefined in their prototype, for example, Object.prototype.toString is different from Array.prototype.toString, to apply a Object.prototype.toString to an array object, we can write the following code var toString...
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jquery

using each function over "for" construct

jquery.each jQuery.each("Boolean Number String Function Array Date RegExp Object".split(" "), function(i, name) { class2type[ "[object " + name + "]" ] = name.toLowerCase(); });
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Software Design

Semantics only works in a context

I am a believer of semantics. What is why name the domain as semanticsworks.com. But let me take a step back to explain what I mean semantics here. You may find the definition in...
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misc

Stop fighting

JavaScript is a amazing language, and it continues to amaze me. But I learned it in the hard way because I was trying to translate it into classic OO concept, and I failed. Douglas...
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