The loading of a .json file from a hard disk is an asynchronous operation, and thus it needs to specify a callback function to execute after the file is loaded.

function readTextFile(file, callback) {
    var rawFile = new XMLHttpRequest();
    rawFile.overrideMimeType("application/json");
    rawFile.open("GET", file, true);
    rawFile.onreadystatechange = function() {
        if (rawFile.readyState === 4 && rawFile.status == "200") {
            callback(rawFile.responseText);
        }
    }
    rawFile.send(null);
}

//usage:
readTextFile("/Users/Documents/workspace/test.json", function(text){
    var data = JSON.parse(text);
    console.log(data);
});

This function also works for loading a .html or .txt files, by overriding the mime type parameter to "text/html", "text/plain", etc.

This solution uses an Asynchronous call. It will likely work better than a synchronous solution.

var request = new XMLHttpRequest();
request.open("GET", "../../data/file.json", false);
request.send(null);
request.onreadystatechange = function() {
  if ( request.readyState === 4 && request.status === 200 ) {
    var my_JSON_object = JSON.parse(request.responseText);
    console.log(my_JSON_object);
  }
}

You have to loop with for in. You can try this code below.

Actually it is too hard to build an output like your expected output, because your data and your expected output is difference.

const nameJson = '{"Name": "name", "Jab1": 2, "Jab1_OS": -14, "Jab2": 2, "Jab2_OS": -16, "Jab3": 3, "Jab3_OS": -29, "Ftilt": 5, "Ftilt_OS": -13, "Uptilt": 5, "Uptilt_OS": -18, "Dtilt": 5, "Dtilt_OS": -15, "Fair": 16,"Fair_OS": -12,"UpB": 3,"UpB_OS": -20,"Bair": 6,"Bair_OS": -2,"Dair": 5,"Dair_OS": -11,"Upair": 4,"Upair_OS": -3}'
  const data = JSON.parse(nameJson);
  let name = []
  for (const key in data) {
    if (Object.hasOwnProperty.call(data, key)) {
      let toPush = {}
      toPush[key] = data[key]
      name.push(toPush);
    }
  }
  console.log(name)