将RGB转换为HEX问题

Question

according to one of StackOverflow topics I tried to create own RGB to HEX colors converter.

I don't know why but instead converting it double RGB numbers.

So when input is rgb(0, 128, 192) it console out #00128192 .

My code is:

fromRGB: {
    toHEX: {
        supportFunc: function(number) {
            var hex = number.toString(16);
            return hex.length == 1 ? '0' + hex : hex;
        },
        convert: function(r, g, b) {
            var lol = '#' + this.supportFunc(r) + this.supportFunc(g) + this.supportFunc(b);
            console.log(lol);
        }
    },
    prepareAndExecute: function(color_field) {
        // preparing
        var numbers = color_field.match(/\d+/g);
        if(numbers.length == 3) {
            this.toHEX.convert(numbers[0], numbers[1], numbers[2]);
        } else {
            alert('wrong RGB number format');
        }


        //this.toHSL(preparedValue);
    }
}

I execute prepare function, lol variable is the one that should contains converted color in HEX format.

What is wrong with my code, why it doesn't work?

Answer 1

Explanation:

It's because you're passing strings not numbers to supportFunc .

The result of match in prepareAndExecute is an array of strings, thus when you call toString in supportFunc , you are calling String.prototype.toString (not Number.prototype.toString ) which return the string as is.

Solution:

In supportFunc , convert number to a number before using toString :

var hex = Number(number).toString(16);                       // using Number to convert a string to a number (you can use parseInt or unary + if you like)

or convert them before passing them to convert :

this.toHEX.convert(+numbers[0], +numbers[1], +numbers[2]);   // using unary +