What does |0 do in Javascript? [duplicate]

问题

This question already has answers here:

What does the “|” (single pipe) do in JavaScript? (4 answers)

What is this asm style “x | 0” some javascript programmers are now using? (4 answers)

Closed 4 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?

回答1:

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

来源：https://stackoverflow.com/questions/33367264/what-does-0-do-in-javascript