LinkedIn Query

gistfile1.txt

First of all let's clear the things we have used in this conversion



1. Why toString(16) only?

2. Role of 1<<24

3. Role of Slice function



Answer 1: 



Hexadecimal is base 16. 

Break down the words: hexa, meaning 6; decimal, meaning 10. 

Therefore, 10 + 6 = 16 (So, as we are converting to hexadecimal, that's why we are using toString(16) method



Answer 2:



Now your main question comes into play, What << does?



<< is known as the left shift operator, when you write 1<<4 means we are adding 4 zeros at the last or right side shifting 1 to the left side i.e giving us the number in binary form 10000, now we convert this number to its various variants like Decimal, Octal, Hexa-Decimal versions



1<<4 in Binary is equals to 10000

1<<4 in Decimal is equals to 16

1<<4 in Hexadecimal equals to 10

1<<4 in Octal equals to 20



Similarly, 1<<24 looks like as shown below



1<<24 in Binary is equals to 1000000000000000000000000

1<<24 in Decimal is equals to 16777216

1<<24 in Hexadecimal equals to 1000000

1<<24 in Octal equals to 100000000		



Let Clarify it more with an example 

Suppose, r and g were both zero and b was 51



0<<16 gives 0

0<<8 gives 0

51



(0+0+51).toString(16) gives 33



If 1<<24 is not used, we will get #33 (which is not valid hexcolor), so that why, to give our hexcolorcode left padded 

zeroes, whenever no value to r or g is assigned as we did in our example



1<<24 gives 1000000

adding 1 << 24 and we get "1000033". 



Answer 3:



Now to remove the extra one added in 1000033 we used slice, So that we can get 000033, which finally gives us #000033 as per our return statement.

To verify go to any rgb to hex color conversion tool online and enter rgb(0,0,51) you will get #000033