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?
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"
+ you can also use Number as a function: Number(d).toString(16), which might be better for maintenance as it's a bit more obvious what is occurring. Or not.
+, but in this case, we're performing a simple, one-line helper function that has a very obvious purpose in life and can be effectively treated as a black box by any future developers, so maintainability is not really a concern. If this were a line of code in the middle of a larger, more complex method, I would certainly suggest using the Number constructor for clarity's sake.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).
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.
let returnedHex = Number(var_value).toString(16);
also works
