I'm currently attempting to emulate the functionality of JavaScript bit-shift and bitwise operations in Java.
Have you ever tried to accomplish this task, and how can it be done reliably and consistently even when dealing with long integers?
var i=[some array with large integers];
for(var x=0;x<100;x++)
{
var a=a large integer;
var z=some 'long'>2.1 billion;
//EDIT:
z=i[x]+=(z>>>5)^(a<<2))+((z<<4)^(a<<5));
}
How would you transform this into Java code?
Absolutely! Java includes efficient bit-wise operators as well as handy shift operators for various operations.
Is there a specific query you have regarding these operators?
By the way, remember to convert to an int before performing any shifts for accurate results.
int zz = ((int) 123456789123L) << 20;
When you execute the above code, you should receive -1473249280, similar to what you observed in JavaScript.
Additionally, if you need an example like the following, it can be provided:
long[] i=[an array containing large integers];
for(int x=0; x < 100; x++)
{
int a= (int) <a large integer>; // Ensure casting if needed for compatibility
long z= <a 'long' exceeding 2.1 billion>;
z=i[x]+=((int) z)>>>5)^(a<<2));
}
When working with Java's bitwise operators, it's important to understand the subtle differences between them. Although they generally behave the same, there are some key distinctions to keep in mind.
One such difference is seen in the comparison between Java's int type and JavaScript's >>> operator. While Java's int type is a 32-bit signed value, JavaScript's >>> operator returns a 32-bit unsigned integer value. This distinction becomes evident when looking at the following example:
"" + ((1 << 31) >>> 0)
In JavaScript, this expression evaluates to
"2147483648"
but in Java, it results in
"-2147483648"
To ensure consistent results when performing bit manipulation in Java, it is advisable to use the long type, which provides the necessary precision. However, it's crucial to remember to mask it to 32 signed bits when utilizing the >>> operator with a shift amount of 0 (or a multiple of 32).
To extract the 32 low bits of a long in Java, you can achieve this by performing the following operation:
(myLong & 0xffffffffL)
To convert bitshift and addition operations from JavaScript to Java, one approach is to use int casts to isolate the operands of a bit shift operation, and long casts to isolate operands of an addition or subtraction operation. This is necessary because in Java, an addition operation exceeding 2 billion will be cast to an int automatically if long casts are not used, and in JavaScript, longs are automatically cast to ints in bitshifts which Java does not do automatically:
long result = (long) (((int) z >> 5) ^ ((int) a << 2)) + (long) (((int) z << 4) ^ ((int) a << 5));
I've been working on this jsfiddle: https://jsfiddle.net/3ncyxnzt/ Currently, the red box stops at a specified margin from the top of the page but I want it to also stop before reaching the bottom, so that it doesn't go under or over the footer. ...
Hello there, Let me paint you a picture: for (j = 0; j < btnArr.length; j++) { var btn = document.createElement("button"); btn.addEventListener("click", function() { press(this, j) }, false); div.appendChild(btn); } The issue at hand is t ...
Can the vote button be centered in the script below? <script type="text/javascript" charset="utf-8" src="http://static.polldaddy.com/p/6352993.js"></script> <noscript><a href="http://polldaddy.com/poll/6352993/">This is a le ...
Recently, I've been exploring jQuery Javascript Templates and trying to follow a tutorial that involves fetching tweets from Twitter. The tutorial can be found here: . After carefully implementing the code as instructed, you can view my progress on t ...
Here is some of my custom plugin code (function ($) { $.fn.createGallery = function(options) { var theObject = $(this); var settings = $.extend({ // Default settings. server: 'http://localhost/jQuery%20Gall ...
http://jsfiddle.net/G8djC/2/ Looking to create a tabbed area where content changes based on the tab clicked. The Javascript function switches the link class to active upon clicking. However, struggling to change the color of the active tab beyond the firs ...
I have been working on a website that involves carpooling with drivers and passengers. When a driver submits their details, they are directed to a URL where they can select the passenger they want to ride with. Here is the code snippet I have written: ap ...
Whenever I send a delete request to my node.js server, it can only delete one item from my JSON file until the server restarts. If I attempt to make a second delete request, it successfully deletes the item but also reverts the deletion of the last item. ...
In my Codeigniter framework and bootstrap installation, I have multiple sub-pages. On one of these pages, I am attempting to implement an infinite scroll loader using a jQuery script from a tutorial found at gridScrollFx.js. Here is the JS file I am using: ...
I'm facing a basic issue here. I have a JSON file named pageDefinition.json that is being loaded into my component. Here's how the JSON data looks: ... "testArray": [ {"id": 0, "name": "row1"}, {"id": 1, "name": "row2"}, {"id": 2, "n ...
When it comes to mapping object values with all primitive types, the process is quite straightforward: type ObjectOf<T> = { [k: string]: T }; type MapObj<Obj extends ObjectOf<any>> = { [K in keyof Obj]: Obj[K] extends string ? Obj[K] : ...
Within a text field input lies the value of a database attribute (ref). Upon focusing on the field, a border appears and disappears upon clicking out. My dilemma is that I wish for the data within the text field to be saved in the database without the nee ...
Is it possible to separate pinia actions into two distinct namespaces, allowing access through properties n1 and n2 like this: // current store.n1a('hi') store.n2b() // wanted store.n1.a('hi') store.n2.b() // cumbersome workaround: sto ...
I'm currently working on a web system aimed at monitoring values from a database, and I have the requirement to trigger a sound alert when a specific range of values is received. Despite trying various examples found online, none of them have been suc ...
I'm encountering an issue with my Lambda function being called through API Gateway. Whenever the Lambda triggers a spawn call on a child_process object, the API Gateway immediately returns a 504 timeout error. Despite having set the API gateway timeou ...
Having trouble passing a parameter to the class for handling AJAX errors. The initial function is as follows: function GetLastChangePass(UserId) { var field = { id: UserId, } var fieldStringified = JSON.stringify(field) $.ajax({ ...
When a user clicks on different image or color options, I want to change the main image displayed. Below are the links to the alternative images: https://i.sstatic.net/DxJEb.jpg This is the HTML code: <div class="container"> <p class="img-main" ...
Is there a way to apply a CSS attribute to a specific element (like a div) for only 2 seconds? Here is what I have tried so far: HTML: <div class="custom-div">bar</div> <input class="button" type="button" value="press me" /> JQuery: $ ...
Despite extensive research, I have yet to find an answer to my specific problem. Within a model window, I have a textarea element: <div class="form-group"> <label for="groupDescription" class="col-sm-2 control-label"> Descripti ...
Despite my best efforts scouring the internet for a solution, I have yet to find a method to resolve my issue. The problem lies with my nuxt.js SPA being blocked by my company firewall when accessed by other users at the designated host/port. While servin ...