Gangmax Blog

自由之思想,独立之精神

What Is This in JavaScript?

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From here and here.

What is this?

The JavaScript this keyword refers to the object it belongs to.

It has different values depending on where it is used:

In a method, this refers to the owner object.

Alone, this refers to the global object.

In a function, this refers to the global object.

In a function, in strict mode, this is undefined.

In an event, this refers to the element that received the event.

Methods like call(), and apply() can refer this to any object.

ElasticSearch, Miniconda and Jupyter

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This is a guide how to use ElasticSearch with Python and Jupyter.

To make the Jupyter works on my environment, I want to create a “miniconda” virtual environment, which caused error with “pyenv”. Here is the instructions how to make it work.

Pouring Homebrew

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When running the ”brew” command to install a formula, I always see the “Pouring …” output in console. What does that mean? So I googled “pouring homebrew” and found this. Interesting…

What Is Merkle DAG

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From here.

A Merkle DAG is a Merkle directed acyclic graph. That is a data structure similar to a Merkle tree but not so strict: such DAG does not need to be balanced and its non-leaf nodes are allowed to contain data.