What does |0 do in Javascript? [duplicate] - javascript

This question already has answers here:
What does the "|" (single pipe) do in JavaScript?
(5 answers)
What is this asm style "x | 0" some javascript programmers are now using?
(4 answers)
Closed 7 years ago.
I have been looking into asm.js to use for a project recently, and I noticed that very often the asm.js compiled code will end a statement with |0;, even seemingly redundantly as in the statement i = i|0;
This is not something I have encountered in Javascript code before. What is it for?
EDIT
I don't believe this is duplicate. I know what a bitwise or is. I am specifically asking here why one might use it to or with a 0 before assignment. What purpose does that serve?

Convert to integer and apply a bitwise or with 0. Basically a short form of Math.floor().

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I visited some sites like MWD w3school and etc but I could notice that. also, check the answers in the stack overflow but in want to know to compare these symbols.

With and without the quantifier {1} has same effect? [duplicate]

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Is there any difference between the regular expressions:-
/^[1-9][0-9]+$/
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in which situation I must put a semi colon at the end of a statement? [duplicate]

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In most cases, we can omit semi colon at the end of a statement. But there is a exception I can tell.
isGreenBottleFull && clearGreenBottle()
isRedBottleFull && clearRedBottle()
If you omit the semi colons, the behavior will be strange.
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Semicolons in JavaScript are rarely required for code to execute properly, however are considered a best practice for code quality.
I would recommend this reference as a guide:
https://www.codecademy.com/en/forum_questions/507f6dd09266b70200000d7e

How can I write javascript like this ruby code (array matching)? [duplicate]

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Simplest code for array intersection in javascript
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Closed 9 years ago.
This is my ruby code.
array1= [1,2,3,4,5]
array2= [2,3,4,5,6]
if (array1 & array2).size == 4
puts "4 match"
How can I write the same thing in javascript? Is there any material like ruby-doc in javascript?
There isn't a native method do do it.
Have a look at here : Simplest code for array intersection in javascript
The best documentation I know about javascript and html5 is the Mozilla developer network.

why break this up javascript fragment? [duplicate]

This question already has answers here:
Closed 12 years ago.
Possible Duplicate:
Why split the <script> tag when writing it with document.write()?
I don't really do Javascript programming and was hard to google this but have seen something like this in a couple of different places (by good developers):
document.writeln('<scr'+'ipt src="'+pcheck+'" type="text/javascript"></scr'+'ipt>');
With the split always between the r and the i. What does this achieve?
This is to prevent any script blockers from loading this script, because they cannot find the "script" word within the text.

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