JSFiddle - React, Tailwind, and code Playground

JavaScript

$.getJSON('https://gbdev.io/gb-opcodes/Opcodes.json', function(data) {
	let output = "";
	let myCode = ["21", "E4", "DD", "3E", "AA", "77", "23", "77", "3E", "01", "EA", "EA", "DD", "03"];
  let pointer = 0;
  while(myCode[pointer]){
  	const id = "0x"+myCode[pointer];
    const obj = data.unprefixed[id];
    let line = obj.mnemonic;
    for(const operand of obj.operands){
    	if(operand.name == "d8"){
      	pointer++;
        line += ", " + myCode[pointer];
      }
      else if(operand.name == "d16"){
      	pointer++;
      	const last = myCode[pointer]
        pointer++;
        line += ", " + myCode[pointer]+last;
      }
      else {
      	let res = "";
      	if(!operand.immediate){
        	res = "(" + operand.name + "),";
        }
        else {
        	res = operand.name;
        }
    		line += " " + res;
      }
    }
    console.log(line);
  	pointer++;
  }
  console.log(output);
});