如何在 JavaScript 中将数字表示为十六进制？

Question

I am trying to convert a DEC number to HEX using JavaScript.

The number I am trying to convert is 28.

I have tried using:

function h2d(h) {return parseInt(h,16);}

however it returns 40

I have also tried using:

function d2h(d) {return d.toString(16);}

however it returns 28

The final result should return 1C but I can't seem to work it out.

Does anyone know where I have gone wrong?

Answer 1

It sounds like you're having trouble because your input is a String when you're looking for a number. Try changing your d2h() code to look like this and you should be set:

function d2h(d) { return (+d).toString(16); }

The plus sign ( + ) is a shorthand method for forcing a variable to be a Number. Only Number's toString() method will take a radix, String's will not. Also, your result will be in lowercase, so you might want to force it to uppercase using toUpperCase() :

function d2h(d) { return (+d).toString(16).toUpperCase(); }

So the result will be:

d2h("28") //is "1C"

Answer 2

Duplicate question

(28).toString(16)

The bug you are making is that "28" is a string, not a number. You should treat it as a number. One should not generally expect the language to be able to parse a string into an integer before doing conversions (well... I guess it's reasonable to expect the other way around in javascript).

Answer 3

d2h() as written should work fine:

js> var d=28
js> print(d.toString(16))
1c

How did you test it?

Also, 40 is the expected output of d2h(28), since hexadecimal "28" is decimal 40.

Answer 4

let returnedHex = Number(var_value).toString(16);

也有效