three.js variable

Question

three.js variable

Having difficulty understanding the current situation, it appears there may be a syntax problem. Just to provide some context, I am relatively new to Javascript but have previous experience with AS3.

Looking at this code:

https://github.com/mrdoob/three.js/blob/master/examples/canvas_lines.html

Specifically, line 34 shows:

camera, scene, renderer;

Initially, I assumed these were global variable declarations and that in line 42, they were local declarations within the init() function.

Line 42 reads:

particles, particle;

Upon experimenting with the code, I noticed that declaring the particle object globally as shown caused the script to fail. However, it worked properly when declared as follows:

var particle;

In addition, removing line 42 also fixed the issue.

What is the reason behind this behavior? Can someone please explain what's happening?

Thank you!

javascript syntax three.js

Answer 1

Answer №1

The coding style of this snippet could use some improvement, in my opinion. While it's not explicitly mentioned, take note that:

let positionX = 0;
let positionY = 0;

const windowWidth = window.innerWidth / 2;
const windowHeight = window.innerHeight / 2;

const DISTANCE = 200;
const AMOUNT_X = 10;
const AMOUNT_Y = 10;

let camera, scene, renderer;

This entire block falls under a single let statement, utilizing commas to extend the declaration across multiple lines. Understanding this might assist in clarifying any confusion and organizing your variable assignments more effectively.

Answer 2

The coding style of this snippet could use some improvement, in my opinion. While it's not explicitly mentioned, take note that:

let positionX = 0;
let positionY = 0;

const windowWidth = window.innerWidth / 2;
const windowHeight = window.innerHeight / 2;

const DISTANCE = 200;
const AMOUNT_X = 10;
const AMOUNT_Y = 10;

let camera, scene, renderer;

This entire block falls under a single let statement, utilizing commas to extend the declaration across multiple lines. Understanding this might assist in clarifying any confusion and organizing your variable assignments more effectively.

Answer 3

Answer №2

Line 42 is confirmed to be

particles, particle;

However, line 41 includes

var container, separation = 100, amountX = 50, amountY = 50,

Therefore, the complete statement is (written on a single line)

var container, separation = 100, amountX = 50, amountY = 50, particles, particle;

I don't mean to sound rude, but it may be beneficial to review the code more attentively in the future.

Answer 4

Line 42 is confirmed to be

particles, particle;

However, line 41 includes

var container, separation = 100, amountX = 50, amountY = 50,

Therefore, the complete statement is (written on a single line)

var container, separation = 100, amountX = 50, amountY = 50, particles, particle;

I don't mean to sound rude, but it may be beneficial to review the code more attentively in the future.

Answer 5

Answer №3

Local variables 'particles' and 'particle' are defined in line 42, but only 'particle' is utilized within the local scope. It's advisable to keep variables local in JavaScript for best practices. If line 42 is removed, 'particle' becomes a global variable. However, since 'particle' is not needed outside the function, it's preferred to declare it as a local variable within the function.

JavaScript is known for its simplicity. Additional references can be found at http://www.w3schools.com/js and http://www.javascriptkit.com

Answer 6

Local variables 'particles' and 'particle' are defined in line 42, but only 'particle' is utilized within the local scope. It's advisable to keep variables local in JavaScript for best practices. If line 42 is removed, 'particle' becomes a global variable. However, since 'particle' is not needed outside the function, it's preferred to declare it as a local variable within the function.

JavaScript is known for its simplicity. Additional references can be found at http://www.w3schools.com/js and http://www.javascriptkit.com

three.js variable

Answer №1

Answer №2

Answer №3

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