How do I write a RGB color value in JavaScript?
I am trying to change the color of the function swapFE() below and I can't figure out how to write it. I was told to change the color of the phrase node to the color value (155, 102, 102). I tried to do that as you can see at the end of the function see- parent.childNodes[1].style.color= (155, 102, 102); but it just come开发者_开发问答s out a dark navy blue. It's supposed to be a brownish red. I have no idea what I'm doing wrong. How can I fix this to get the correct RGB color? I know I have the rest right it's just figuring out how to write the color and the value that's giving me problems. Thanks!
//this function changes the French phrase to an English phrase.
function swapFE(e) {
var phrase = e.srcElement;
//phrase.innerText = english[phrase.id];
var parent = phrase.parentNode;
//childNodes[0] is the number of the phrase +1
var idnum = parent.childNodes[0];
//parseInt takes a textstring and extracts it to make a number. Then you will subtract 1 from the number.
var phrasenum = parseInt(idnum.innerHTML)-1;
phrase.innerText = english[phrasenum];
parent.childNodes[1].style.fontStyle= "normal";
parent.childNodes[1].style.color= (155, 102, 102);
}
function swapEF(e) {
var phrase = e.srcElement;
//phrase.innerText = english[phrase.id];
var parent = phrase.parentNode;
var idnum = parent.childNodes[0];
var phrasenum = parseInt(idnum.innerHTML)-1;
phrase.innerText = french[phrasenum];
parent.childNodes[1].style.fontStyle= "italic";
parent.childNodes[1].style.color= "black";
try:
parent.childNodes[1].style.color = "rgb(155, 102, 102)";
Or
parent.childNodes[1].style.color = "#"+(155).toString(16)+(102).toString(16)+(102).toString(16);
Here's a simple function that creates a CSS color string from RGB values ranging from 0 to 255:
function rgb(r, g, b){
return "rgb("+r+","+g+","+b+")";
}
Alternatively (to create fewer string objects), you could use array join():
function rgb(r, g, b){
return ["rgb(",r,",",g,",",b,")"].join("");
}
The above functions will only work properly if (r, g, and b) are integers between 0 and 255. If they are not integers, the color system will treat them as in the range from 0 to 1. To account for non-integer numbers, use the following:
function rgb(r, g, b){
r = Math.floor(r);
g = Math.floor(g);
b = Math.floor(b);
return ["rgb(",r,",",g,",",b,")"].join("");
}
You could also use ES6 language features:
const rgb = (r, g, b) =>
`rgb(${Math.floor(r)},${Math.floor(g)},${Math.floor(b)})`;
this is better function
function RGB2HTML(red, green, blue)
{
var decColor =0x1000000+ blue + 0x100 * green + 0x10000 *red ;
return '#'+decColor.toString(16).substr(1);
}
I am showing with an example of adding random color. You can write this way
var r = Math.floor(Math.random() * 255);
var g = Math.floor(Math.random() * 255);
var b = Math.floor(Math.random() * 255);
var col = "rgb(" + r + "," + g + "," + b + ")";
parent.childNodes[1].style.color = col;
The property is expected as a string
ES6 (template literal) helper functions:
function rgba(r, g, b, a=1){
return `rgba(${r}, ${g}, ${b}, ${a})`
}
function rgb(r, g, b){
return `rgb(${r}, ${g}, ${b})`
}
Similar to asd's answer but faster and simpler (using bitwise operations):
function rgb(red, green, blue) {
return (red & 0xF0 ? '#' : '#0') + (red << 16 | green << 8 | blue).toString(16)
}
dec2hex = function (d) {
if (d > 15)
{ return d.toString(16) } else
{ return "0" + d.toString(16) }
}
rgb = function (r, g, b) { return "#" + dec2hex(r) + dec2hex(g) + dec2hex(b) };
and:
parent.childNodes[1].style.color = rgb(155, 102, 102);
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