Develop Reference

Why does not JS background colour of input field check work? [duplicate]

Using the following jQuery will get the RGB value of an element's background color:
$('#selector').css('backgroundColor');
Is there a way to get the hex value rather than the RGB?

TL;DR
Use this clean one-line function with both rgb and rgba support:
const rgba2hex = (rgba) => `#${rgba.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+)(?:,\s*(\d+\.{0,1}\d*))?\)$/).slice(1).map((n, i) => (i === 3 ? Math.round(parseFloat(n) * 255) : parseFloat(n)).toString(16).padStart(2, '0').replace('NaN', '')).join('')}`
2021 updated answer
Much time has passed since I originally answered this question. Then cool ECMAScript 5 and 2015+ features became largely available on browsers, like arrow functions, Array.map, String.padStart and template strings. Since some years, it's possible to write cross-browser one-liner rgb2hex:
const rgb2hex = (rgb) => `#${rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/).slice(1).map(n => parseInt(n, 10).toString(16).padStart(2, '0')).join('')}`
// Use as you wish...
console.log(rgb2hex('rgb(0,0,0)'))
console.log(rgb2hex('rgb(255, 255, 255)'))
console.log(rgb2hex('rgb(255,0,0)'))
console.log(rgb2hex('rgb(38, 170, 90)'))
It works by using a regular expression to get each digit inside the rgb string, slice(1) to get only the digits (the first result of match is the full string itself), map to iterate through each digit, each iteration converting to Number with parseInt, then back to an hexadecimal String (through a base-16 conversion), adding zero if needed via padStart. Finally, join each converted/adjusted digit to a unique String starting with '#'.
Of course, we could extend it without much effort as an one-liner rgba2hex:
const rgba2hex = (rgba) => `#${rgba.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+)(?:,\s*(\d+\.{0,1}\d*))?\)$/).slice(1).map((n, i) => (i === 3 ? Math.round(parseFloat(n) * 255) : parseFloat(n)).toString(16).padStart(2, '0').replace('NaN', '')).join('')}`
// Now it doesn't matter if 'rgb' or 'rgba'...
console.log(rgba2hex('rgb(0,0,0)'))
console.log(rgba2hex('rgb(255, 255, 255)'))
console.log(rgba2hex('rgb(255,0,0)'))
console.log(rgba2hex('rgb(38, 170, 90)'))
console.log(rgba2hex('rgba(255, 0, 0, 0.5)'))
console.log(rgba2hex('rgba(0,255,0,1)'))
console.log(rgba2hex('rgba(127,127,127,0.25)'))
And that's it. But if you want to dive deep in the old school JavaScript world, keep reading.
Original 2010 answer
Here is the cleaner solution I wrote based on #Matt suggestion:
function rgb2hex(rgb) {
rgb = rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
function hex(x) {
return ("0" + parseInt(x).toString(16)).slice(-2);
}
return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
}
Some browsers already returns colors as hexadecimal (as of Internet Explorer 8 and below). If you need to deal with those cases, just append a condition inside the function, like #gfrobenius suggested:
function rgb2hex(rgb) {
if (/^#[0-9A-F]{6}$/i.test(rgb)) return rgb;
rgb = rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
function hex(x) {
return ("0" + parseInt(x).toString(16)).slice(-2);
}
return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
}
If you're using jQuery and want a more complete approach, you can use CSS Hooks available since jQuery 1.4.3, as I showed when answering this question: Can I force jQuery.css("backgroundColor") returns on hexadecimal format?

var hexDigits = new Array
("0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f");
//Function to convert rgb color to hex format
function rgb2hex(rgb) {
rgb = rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
}
function hex(x) {
return isNaN(x) ? "00" : hexDigits[(x - x % 16) / 16] + hexDigits[x % 16];
}
(Source)

Most browsers seem to return the RGB value when using:
$('#selector').css('backgroundColor');
Only I.E (only 6 tested so far) returns the Hex value.
To avoid error messages in I.E, you could wrap the function in an if statement:
function rgb2hex(rgb) {
if ( rgb.search("rgb") == -1 ) {
return rgb;
} else {
rgb = rgb.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+)(?:,\s*(\d+))?\)$/);
function hex(x) {
return ("0" + parseInt(x).toString(16)).slice(-2);
}
return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
}
}

Updated #ErickPetru for rgba compatibility:
function rgb2hex(rgb) {
rgb = rgb.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+)(?:,\s*(\d+))?\)$/);
function hex(x) {
return ("0" + parseInt(x).toString(16)).slice(-2);
}
return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
}
I updated the regex to match the alpha value if defined, but not use it.

Here's an ES6 one liner that doesn't use jQuery:
var rgb = document.querySelector('#selector').style['background-color'];
return '#' + rgb.substr(4, rgb.indexOf(')') - 4).split(',').map((color) => parseInt(color).toString(16).padStart(2, '0')).join('');

Here is a version that also checks for transparent, I needed this since my object was to insert the result into a style attribute, where the transparent version of a hex color is actually the word "transparent"..
function rgb2hex(rgb) {
if ( rgb.search("rgb") == -1 ) {
return rgb;
}
else if ( rgb == 'rgba(0, 0, 0, 0)' ) {
return 'transparent';
}
else {
rgb = rgb.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+)(?:,\s*(\d+))?\)$/);
function hex(x) {
return ("0" + parseInt(x).toString(16)).slice(-2);
}
return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
}
}

Short
// c - color str e.g."rgb(12,233,43)", result color hex e.g. "#0ce92b"
let rgb2hex=c=>'#'+c.match(/\d+/g).map(x=>(+x).toString(16).padStart(2,0)).join``
// rgb - color str e.g."rgb(12,233,43)", result color hex e.g. "#0ce92b"
let rgb2hex= c=> '#'+c.match(/\d+/g).map(x=>(+x).toString(16).padStart(2,0)).join``
console.log(rgb2hex("rgb(12,233,43"));

Function that returns background color of an element in hex.
function getBgColorHex(elem){
var color = elem.css('background-color')
var hex;
if(color.indexOf('#')>-1){
//for IE
hex = color;
} else {
var rgb = color.match(/\d+/g);
hex = '#'+ ('0' + parseInt(rgb[0], 10).toString(16)).slice(-2) + ('0' + parseInt(rgb[1], 10).toString(16)).slice(-2) + ('0' + parseInt(rgb[2], 10).toString(16)).slice(-2);
}
return hex;
}
usage example:
$('#div1').click(function(){
alert(getBgColorHex($(this));
}
jsfiddle

Readable && Reg-exp free (no Reg-exp)
I've created a function that uses readable basic functions and no reg-exps.
The function accepts color in hex, rgb or rgba CSS format and returns hex representation.
EDIT: there was a bug with parsing out rgba() format, fixed...
function getHexColor( color ){
//if color is already in hex, just return it...
if( color.indexOf('#') != -1 ) return color;
//leave only "R,G,B" :
color = color
.replace("rgba", "") //must go BEFORE rgb replace
.replace("rgb", "")
.replace("(", "")
.replace(")", "");
color = color.split(","); // get Array["R","G","B"]
// 0) add leading #
// 1) add leading zero, so we get 0XY or 0X
// 2) append leading zero with parsed out int value of R/G/B
// converted to HEX string representation
// 3) slice out 2 last chars (get last 2 chars) =>
// => we get XY from 0XY and 0X stays the same
return "#"
+ ( '0' + parseInt(color[0], 10).toString(16) ).slice(-2)
+ ( '0' + parseInt(color[1], 10).toString(16) ).slice(-2)
+ ( '0' + parseInt(color[2], 10).toString(16) ).slice(-2);
}

Same answer like #Jim F answer but ES6 syntax , so, less instructions :
const rgb2hex = (rgb) => {
if (rgb.search("rgb") === -1) return rgb;
rgb = rgb.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+)(?:,\s*(\d+))?\)$/);
const hex = (x) => ("0" + parseInt(x).toString(16)).slice(-2);
return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
};

color class taken from bootstrap color picker
// Color object
var Color = function(val) {
this.value = {
h: 1,
s: 1,
b: 1,
a: 1
};
this.setColor(val);
};
Color.prototype = {
constructor: Color,
//parse a string to HSB
setColor: function(val){
val = val.toLowerCase();
var that = this;
$.each( CPGlobal.stringParsers, function( i, parser ) {
var match = parser.re.exec( val ),
values = match && parser.parse( match ),
space = parser.space||'rgba';
if ( values ) {
if (space === 'hsla') {
that.value = CPGlobal.RGBtoHSB.apply(null, CPGlobal.HSLtoRGB.apply(null, values));
} else {
that.value = CPGlobal.RGBtoHSB.apply(null, values);
}
return false;
}
});
},
setHue: function(h) {
this.value.h = 1- h;
},
setSaturation: function(s) {
this.value.s = s;
},
setLightness: function(b) {
this.value.b = 1- b;
},
setAlpha: function(a) {
this.value.a = parseInt((1 - a)*100, 10)/100;
},
// HSBtoRGB from RaphaelJS
// https://github.com/DmitryBaranovskiy/raphael/
toRGB: function(h, s, b, a) {
if (!h) {
h = this.value.h;
s = this.value.s;
b = this.value.b;
}
h *= 360;
var R, G, B, X, C;
h = (h % 360) / 60;
C = b * s;
X = C * (1 - Math.abs(h % 2 - 1));
R = G = B = b - C;
h = ~~h;
R += [C, X, 0, 0, X, C][h];
G += [X, C, C, X, 0, 0][h];
B += [0, 0, X, C, C, X][h];
return {
r: Math.round(R*255),
g: Math.round(G*255),
b: Math.round(B*255),
a: a||this.value.a
};
},
toHex: function(h, s, b, a){
var rgb = this.toRGB(h, s, b, a);
return '#'+((1 << 24) | (parseInt(rgb.r) << 16) | (parseInt(rgb.g) << 8) | parseInt(rgb.b)).toString(16).substr(1);
},
toHSL: function(h, s, b, a){
if (!h) {
h = this.value.h;
s = this.value.s;
b = this.value.b;
}
var H = h,
L = (2 - s) * b,
S = s * b;
if (L > 0 && L <= 1) {
S /= L;
} else {
S /= 2 - L;
}
L /= 2;
if (S > 1) {
S = 1;
}
return {
h: H,
s: S,
l: L,
a: a||this.value.a
};
}
};
how to use
var color = new Color("RGB(0,5,5)");
color.toHex()

Just to add to #Justin's answer above..
it should be
var rgb = document.querySelector('#selector').style['background-color'];
return '#' + rgb.substr(4, rgb.indexOf(')') - 4).split(',').map((color) => String("0" + parseInt(color).toString(16)).slice(-2)).join('');
As the above parse int functions truncates leading zeroes, thus produces incorrect color codes of 5 or 4 letters may be... i.e. for rgb(216, 160, 10) it produces #d8a0a while it should be #d8a00a.
Thanks

This one looks a bit nicer:
var rgb = $('#selector').css('backgroundColor').match(/\d+/g);
var r = parseInt(rgb[0], 10);
var g = parseInt(rgb[1], 10);
var b = parseInt(rgb[2], 10);
var hex = '#'+ r.toString(16) + g.toString(16) + b.toString(16);
a more succinct one-liner:
var rgb = $('#selector').css('backgroundColor').match(/\d+/g);
var hex = '#'+ Number(rgb[0]).toString(16) + Number(rgb[1]).toString(16) + Number(rgb[2]).toString(16);
forcing jQuery to always return hex:
$.cssHooks.backgroundColor = {
get: function(elem) {
if (elem.currentStyle)
var bg = elem.currentStyle["backgroundColor"];
else if (window.getComputedStyle) {
var bg = document.defaultView.getComputedStyle(elem,
null).getPropertyValue("background-color");
}
if (bg.search("rgb") == -1) {
return bg;
} else {
bg = bg.match(/\d+/g);
function hex(x) {
return ("0" + parseInt(x).toString(16)).slice(-2);
}
return "#" + hex(bg[0]) + hex(bg[1]) + hex(bg[2]);
}
}
}

Since the question was using JQuery, here’s a JQuery plugin based on Daniel Elliott’s code:
$.fn.cssAsHex = function(colorProp) {
var hexDigits = '0123456789abcdef';
function hex(x) {
return isNaN(x) ? '00' : hexDigits[(x - x % 16) / 16] + hexDigits[x % 16];
};
// Convert RGB color to Hex format
function rgb2hex(rgb) {
var rgbRegex = rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
return '#' + hex(rgbRegex[1]) + hex(rgbRegex[2]) + hex(rgbRegex[3]);
};
return rgb2hex(this.css(colorProp));
};
Use it like:
var hexBackgroundColor = $('#myElement').cssAsHex('background-color');

Here's a solution I found that does not throw scripting errors in IE:
http://haacked.com/archive/2009/12/29/convert-rgb-to-hex.aspx

Steven Pribilinskiy's answer drops leading zeroes, for example #ff0000 becomes #ff00.
A solution is to append a leading 0 and substring off the last 2 digits.
var rgb = $('#selector').css('backgroundColor').match(/\d+/g);
var hex = '#'+ String('0' + Number(rgb[0]).toString(16)).slice(-2) + String('0' + Number(rgb[1]).toString(16)).slice(-2) + String('0' + Number(rgb[2]).toString(16)).slice(-2);

Improved function "hex"
function hex(x){
return isNaN(x) ? "00" : hexDigits[x >> 4] + hexDigits[x & 0xf];
// or option without hexDigits array
return (x >> 4).toString(16)+(x & 0xf).toString(16);
}

Here is my solution, also does touppercase by the use of an argument and checks for other possible white-spaces and capitalisation in the supplied string.
var a = "rgb(10, 128, 255)";
var b = "rgb( 10, 128, 255)";
var c = "rgb(10, 128, 255 )";
var d = "rgb ( 10, 128, 255 )";
var e = "RGB ( 10, 128, 255 )";
var f = "rgb(10,128,255)";
var g = "rgb(10, 128,)";
var rgbToHex = (function () {
var rx = /^rgb\s*\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\)$/i;
function pad(num) {
if (num.length === 1) {
num = "0" + num;
}
return num;
}
return function (rgb, uppercase) {
var rxArray = rgb.match(rx),
hex;
if (rxArray !== null) {
hex = pad(parseInt(rxArray[1], 10).toString(16)) + pad(parseInt(rxArray[2], 10).toString(16)) + pad(parseInt(rxArray[3], 10).toString(16));
if (uppercase === true) {
hex = hex.toUpperCase();
}
return hex;
}
return;
};
}());
console.log(rgbToHex(a));
console.log(rgbToHex(b, true));
console.log(rgbToHex(c));
console.log(rgbToHex(d));
console.log(rgbToHex(e));
console.log(rgbToHex(f));
console.log(rgbToHex(g));
On jsfiddle
Speed comparison on jsperf
A further improvement could be to trim() the rgb string
var rxArray = rgb.trim().match(rx),

My beautiful non-standard solution
HTML
<div id="selector" style="background-color:#f5b405"></div>
jQuery
$("#selector").attr("style").replace("background-color:", "");
Result
#f5b405

Convert RGB to Hex
I am using Jasmine protractor and I was getting errors like
- Expected [ 'rgba(255, 255, 255, 1)' ] to contain '#fff'.
Below function worked fine for me.
function RGBAToHexA(test:string) {
let sep = test.toString().indexOf(",") > -1 ? "," : " ";
const rgba = test.toString().substring(5).split(")")[0].split(sep);
console.log(rgba)
let r = (+rgba[0]).toString(16),
g = (+rgba[1]).toString(16),
b = (+rgba[2]).toString(16),
a = Math.round(+rgba[3] * 255).toString(16);
if (r.length == 1)
r = "0" + r;
if (g.length == 1)
g = "0" + g;
if (b.length == 1)
b = "0" + b;
if (a.length == 1)
a = "0" + a;
return "#" + r + g + b + a;
}
describe('Check CSS', function() {
it('should check css of login page', async function(){
browser.waitForAngularEnabled(true);
browser.actions().mouseMove(element(by.css('.btn-auth, .btn-auth:hover'))).perform(); // mouse hover on button
csspage.Loc_auth_btn.getCssValue('color').then(function(color){
console.log(RGBAToHexA(color))
expect( RGBAToHexA(color)).toContain(cssData.hoverauth.color);
})

To all the Functional Programming lovers, here is a somewhat functional approach :)
const getHexColor = (rgbValue) =>
rgbValue.replace("rgb(", "").replace(")", "").split(",")
.map(colorValue => (colorValue > 15 ? "0" : "") + colorValue.toString(16))
.reduce((acc, hexValue) => acc + hexValue, "#")
then use it like:
const testRGB = "rgb(13,23,12)"
getHexColor(testRGB)

my compact version
//Function to convert rgb color to hex format
function rgb2hex(rgb) {
if(/^#/.test(rgb))return rgb;// if returns colors as hexadecimal
let re = /\d+/g;
let hex = x => (x >> 4).toString(16)+(x & 0xf).toString(16);
return "#"+hex(re.exec(rgb))+hex(re.exec(rgb))+hex(re.exec(rgb));
}

full cases (rgb, rgba, transparent...etc) solution (coffeeScript)
rgb2hex: (rgb, transparentDefault=null)->
return null unless rgb
return rgb if rgb.indexOf('#') != -1
return transparentDefault || 'transparent' if rgb == 'rgba(0, 0, 0, 0)'
rgb = rgb.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+)(?:,\s*(\d+))?\)$/);
hex = (x)->
("0" + parseInt(x).toString(16)).slice(-2)
'#' + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3])

Hi here's my solution after getting the element's color with Javascript
function rgb_hex(rgb_string_js){ //example: "rgb(102,54,255)"
var new_rgb_list = rgb_string_js.replace("rgb(","").replace(")","").split(",");
return ("#" + parseInt(new_rgb_list[0]).toString(16) + parseInt(new_rgb_list[1]).toString(16) + parseInt(new_rgb_list[2]).toString(16));
}

Prefix notation string calculator Javascript problem

I'm making a calculator for a prefix notation string and it has covered all the normal tests that I've added to it. But I've come across one that it doesn't seem to be getting the right answer for and I'm unsure of why it seems to be having a problem with this.
I think it might have something to do with the division and subtraction when it comes to the numbers, because apart of the problem was I needed to assume that all inputs were valid, so there wouldn't be negative numbers nor would there be bad inputs IE not formatted correctly.
Here is the code and some of the test problems I inputted into it.
"+ / * 1 3 + 12 16 * 10 4" = 40.107142857142854
"+ * / - 5 3 / 1 3 + 2 2 / 3 * + 12 16 * 10 4" = 24.00267857142857 --- This is the one it doesn't like
"/ 300000 * + 12 16 * 10 40"= 26.785714285714285
function prefixEval(expression) {
let temp = expression.split(' ')
let expr = temp.reverse()
let stack = []
for (let i = 0; i < expr.length; i++) {
if (
expr[i] === '+' ||
expr[i] === '-' ||
expr[i] === '/' ||
expr[i] === '*'
) {
let j = stack.pop()
let k = stack.pop()
let temp = checkOperator(parseInt(j), parseInt(k), expr[i])
stack.push(temp)
} else {
stack.push(expr[i])
}
}
return stack
}
function checkOperator(a, b, op) {
switch (op) {
case '+':
console.log('adding' + ' ' + a + ' ' + op + ' ' + b)
console.log(a + b)
return a + b
case '-':
console.log('subtracting' + ' ' + a + ' ' + op + ' ' + b)
console.log(a - b)
return a - b
case '/':
console.log('dividing' + ' ' + a + ' ' + op + ' ' + b)
console.log(a / b)
return a / b
case '*':
console.log('multiplying' + ' ' + a + ' ' + op + ' ' + b)
console.log(a * b)
return a * b
default:
return 'this is not correct'
}
}
console.log(prefixEval('+ * / - 5 3 / 1 3 + 2 2 / 3 * + 12 16 * 10 4'))

You are using parseInt and dividing 2 by 0 which produces Infinity . To fix,
Change,
let temp = checkOperator(parseInt(j), parseInt(k), expr[i])
to
let temp = checkOperator(parseFloat(j), parseFloat(k), expr[i])
This is give you the expected answer

pythagorean formula to calculate the perimeter of triangle in Javascript?

i am so newbie in programming. i had problem how to count the area and around of triangle.
i had code code some, but the output results are always wrong calculate.
function fungsiLuasSegitiga(a, b) {
var luas = (1 / 2) * a * b;
return luas;
}
function fungsiKllSegitiga(a, b) {
var c = Math.sqrt(Math.pow(a, 2) + Math.pow(b, 2));
var kll = a + b + c;
return kll;
}
var x = prompt("masukkan nilai alas segitiga!");
var y = prompt("masukkan nilai tinggi segitiga!");
var d = fungsiLuasSegitiga(x, y);
var e = fungsiKllSegitiga(x, y);
alert("luas segitiga adalah " + d);
alert("keliling segitiga adalah " + e);
when i put number 3 and 4, the function fungsiLuasSegitiga count it be 345, but the result must be 12 (3+4+5).

prompt returns a string and not a number. So, kll calculation ends up being "3" + "4" + 5. This concatenates the string instead of summing the numbers. You need to parse it to a number before assigning it to x and y either by using unary plus operator or parseInt
function fungsiLuasSegitiga(a, b) {
var luas = (1 / 2) * a * b;
return luas;
}
function fungsiKllSegitiga(a, b) {
var c = Math.sqrt(Math.pow(a, 2) + Math.pow(b, 2));
var kll = a + b + c;
return kll;
}
var x = +prompt("masukkan nilai alas segitiga!");
var y = +prompt("masukkan nilai tinggi segitiga!");
var d = fungsiLuasSegitiga(x, y);
var e = fungsiKllSegitiga(x, y);
alert("luas segitiga adalah " + d);
alert("keliling segitiga adalah " + e);

Unique in generated random number (no duplicate)

I want only the generated random number will hava no duplicate, whenever i try to put the number, the generated random number has duplicate, any other idea. what should i change here?
See the fiddle
var arr = hello.toString(10).replace(/\D/g, '0').split('').map(Number);
for(i=0;i<arr.length;i++) arr[i] = +arr[i]|0;
//initialize variables
var z = arr[3];
var y = arr[2];
var x = arr[1];
var w = arr[0];
while((((a2 <= 0) || (a2 > 49)) || ((b <= 0) || (b > 49)) || ((c <= 0) || (c > 49)) || ((d <= 0) || (d > 49)) || ((e2 <= 0) || (e2 > 49)) || ((f <= 0) || (f > 49)) || ((g <= 0) || (g > 49) ))){
//loop ulit kapag hindi match yung random number sa value nung z
while( zRandomString != z){
zRandom = Math.floor(Math.random() * (109 - 100 + 1)) + 100;
zRandomRound = zRandom % 10;
zRandomString = zRandomRound.toString();
}
var zNew = zRandom; //new value ng z
document.getElementById("zebra").innerHTML = "Z = " + zNew + "<br />";// udsadsadsad
h = zNew;
while( yRandomString != y){
yRandom = Math.floor(Math.random() * (49 - 1 + 1)) + 1;
yRandomRound = yRandom % 10;
yRandomString = yRandomRound.toString();
}
var yNew = yRandom; //new value ng z
document.getElementById("yeah").innerHTML = "Y = " + yNew + "<br />";// udsadsadsad
h = h - yNew;
while( xRandomString != x){
xRandom = Math.floor(Math.random() * (h - 1 + 1)) + 1;
xRandomRound = xRandom % 10;
xRandomString = xRandomRound.toString();
}
var xNew = xRandom; //new value ng z
document.getElementById("ex").innerHTML = "X = " + xNew + "<br />";// udsadsadsad
h = h - xNew;
while( wRandomString != w){
wRandom = Math.floor(Math.random() * (h - 1 + 1)) + 1;
wRandomRound = wRandom % 10;
wRandomString = wRandomRound.toString();
}
var wNew = wRandom; //new value ng z
document.getElementById("weh").innerHTML = "W = " + wNew + "<br />";// udsadsadsad
//h = Math.abs(h - wNew); // new value of h
h = h - wNew;
a = Math.floor(Math.random() * (wNew - 1 + 1)) + 1;
a2 = wNew - a;
b = Math.floor(Math.random() * (a2 - 1 + 1)) + 1;
c = a - b;
d = yNew;
e = Math.floor(Math.random() * (xNew - 1 + 1)) + 1;
e2 = xNew - e;
f = Math.floor(Math.random() * (e2 - 1 + 1)) + 1;
g = e - f;
}
var combo = a2.toString() + ', ' + b.toString() + ', ' + c.toString() + ', ' + d.toString() + ', ' + e2.toString() + ', ' + f.toString() + ', ' + g.toString() + ', ' + h.toString();
document.getElementById("combo").innerHTML = combo;

Try to use this scheme:
var r;
do {
r = Math.floor(Math.random() * 10);
} while (r == 6);

It is not quite clear what you want, but one way to create a sequence on unique random numbers is to create a pool of numbers and sucessively pick and remove items from it:
function pick(pool) {
if (pool.length == 0) return undefined;
// pick an element from the pool
var k = (Math.random() * pool.length) | 0;
var res = pool[k];
// adjust array
pool[k] = pool[pool.length - 1];
pool.pop();
return res;
}
// example
var pool = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
while (pool.length) {
console.log(pick(pool));
}
Another method is to shoffle the pool first and then pop off elements:
function shuffle(arr) {
var n = arr.length;
while (n) {
// pick element
var k = (Math.random() * n--) | 0;
// swap last and picked elements
var swap = arr[k];
arr[k] = arr[n];
arr[n] = swap;
}
}
var pool = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
shuffle(pool);
while (pool.length) {
console.log(pool.pop());
}
These two methods aren't very different if you look at the pick and shuffle functions. Of course, eventually you will exhaust the pool. You can then decide to recreate or reshuffle the array. Also note that these methods will produce repeated elements if the pool has repeated entries.

javascript - How to reverse bitwise shift?

This is my Function. In this function there is two parameter value and how many bits shift.
function test(Value, ShiftBits) {
return (Value << ShiftBits) | (Value >>> (32 - ShiftBits));
};
Now i want to make reverse of this function. In this test() function if i put
test(105748,7);
it returns 13535744;
Now i need to make a function like, if i put
rev_test(13535744,7);
it returns 105748;
Any help Appreciated.

Why not reverse the logic? I spelled it out below:
Number.prototype.zeroFillBin = function() {
var s = this.toString(2);
while (s.length < 32) s = '0' + s;
return s;
}
function test(val, bits) {
return (val << bits) | (val >>> (32 - bits));
};
function rev_test(val, bits) {
return (val >>> bits) | (val << (32 - bits));
};
x = 105748;
y = test(x, 7); // return 13535744
console.log(x + ' = ' + x.zeroFillBin())
console.log(y + ' = ' + y.zeroFillBin() + '\n');
x = 13535744;
y = rev_test(x, 7); // return 105748
console.log(x + ' = ' + x.zeroFillBin())
console.log(y + ' = ' + y.zeroFillBin() + '\n');
Results:
105748 = 00000000000000011001110100010100
13535744 = 00000000110011101000101000000000
13535744 = 00000000110011101000101000000000
105748 = 00000000000000011001110100010100

105748 << 1 // 13535744
13535744 >> 1 // 105748