parser

/**
 * returns a javascript object from a JSON formatted string
 * Example json to javascript object:
 *   "5"          -> 5
 *   "'hello'"   -> 'hello'
 *   "[]"         -> []
 *   "{}"         -> {}
 *   "["hello"]"  -> ['hello']
 *
 *  For more examples, use the JSON.stringify method in the console
 */

function JSONParser(string) {
  const tests = [isStringNumber, isStringString, isStringBoolean, isStringNull, isStringArray];
  const methods = [turnStringNumberToNumber, turnStringStringToString, turnStringBooleanToBoolean, turnStringNullToNull, turnStringArrayToArray];
  // console.log(string);
  // check if it's number
  if(tests[0](string)) return methods[0](string);
  // check if it's string
  if(tests[1](string)) return methods[1](string);
  // check if it's boolean
  // DON'T USE Boolean Object!! It returns true for any string.
  if(tests[2](string)) return methods[2](string);
  // check if string is null
  if(tests[3](string)) return methods[3](string);

  // check if string is array
  if(tests[4](string)) return methods[4](string);
}
const whichTest = (arrayOfTests, value) => {
  for(let i = 0; i < arrayOfTests.length; i++){
    if(arrayOfTests[i](value)){
      return i;
    }
  }
  return -1;
}
const isStringNumber = (string) => {
  return !isNaN(string);
}
const isStringString = (string) => {
  return string.charAt(0) === '"' && string.charAt(string.length-1) === '"';
}
const isStringBoolean = (string) => {
  return string === "true" || string === "false";
}
const isStringNull = (string) => {
  return string === "null";
}
const isStringArray = (string) => {
  return string.charAt(0) === '[' && string.charAt(string.length-1) === ']';
}
const turnStringNumberToNumber = (string) => {
  return parseInt(string);
}
const turnStringStringToString = (string) => {
  return string.substring(1, string.length - 1);
}
const turnStringBooleanToBoolean = (string) => {
  return string === "true" ? true : false;
}
const turnStringNullToNull = (string) => {
  return null;
}
const turnStringArrayToArray = (string, tests, methods) => {
  // "["a"]" -> ["a"]
  // "[true]" -> [true]
  // "[1]" -> [1]
  // "[false,1,"34"]" -> [false, 1, "34"]
  // "[true,403485,"test"]" -> [true,403485,"test"]
  const parsedString = string.substring(1, string.length - 1);
}