rgbToHex.js

/*
Coding in function ```colorOf```. function accept 3 parameter:```r``` ```g``` ```b```. It means value of color red green and blue. the value range is 0-255.

Use ```toString(16)``` Convert numbers r g b to hex string form. at last, combine them to a web color code and return it.

the color code should starting with "#". and then use 2 characters per color.

for example:

```
colorOf(255,0,0) should return "#ff0000"
colorOf(0,111,0) should return "#006f00"
colorOf(1, 2 ,3) should return "#010203"
*/

//Answer//

const colorOf = (...rgb) => '#' + rgb.map(x => `0${x.toString(16)}`.slice(-2)).join('')

//OR//

let colorOf=(r,g,b)=>'#'+[r,g,b].map(x=>x.toString(16).length===1?'0'+x.toString(16):x.toString(16)).join('')