JSON转数组后，筛选分组并输出，判断键值键值是否存在补0

var arr = [

{“category_name”: “60米”, “member_name”: “张三”, “value”: “90”},

{“category_name”: “60米”, “member_name”: “李四”, “value”: “80”},

{“category_name”: “3000米”, “member_name”: “张三”, “value”: “46”},

{“category_name”: “负重”, “member_name”: “王五”, “value”: “23”},

{“category_name”: “负重”, “member_name”: “马六”, “value”: “85”},

{“category_name”: “100米”, “member_name”: “张三”, “value”: “79”}

];

var NameData = ['张三', '李四', '王五', '马六'];
var projectData = ['60米', '3000米', '负重', '100米'];

/*JSON数据分组转化设置*/
function createTree(arr, keys) {
  function createObj(arr, arrORobj, keys, start) {
    for (let i = 0; i < arr.length; i++) {
      if (start >= keys.length) {
        let newArray = Array.isArray(arrORobj) ? arrORobj : []
        return newArray.concat(arr[i])
      }
      let curKey = keys[start]
      let curVal = arr[i][curKey]
      if (!curVal)continue
      let newObj = arrORobj[curVal] ? arrORobj[curVal] : {}
      arrORobj[curVal] = createObj([arr[i]], newObj, keys, start + 1)
    }
    return arrORobj
  }

  return createObj(arr, {}, keys, 0)
}

//按照名字先分组，后按照项目分类，组成新的数组;
var nv = createTree(arr, ['member_name', 'category_name']);
console.log(nv);


//document.write(JSON.stringify(nv));
//document.write("<hr>");
//读取名字;
//document.write(arr[0].member_name);
//document.write("<br>");
//读取转换数组的值；
//document.write(JSON.stringify(nv[1][1][0]['value']));

//document.write(JSON.stringify(nv[NameData[0]]['60米'][0]['value']));
//document.write(JSON.stringify(nv[NameData[0]]['3000米'][0]['value']));
//document.write(JSON.stringify(nv[NameData[0]]['100米'][0]['value']));
//document.write("<hr>");

//判断数据某键值是否存在；
/*
 function typeArr(newArr, key) {
 if (newArr.hasOwnProperty(key)) {
 return nv[NameData[0]][projectData[key]][0]['value'];
 } else {
 return '0';
 }
 }
 */


//console.log(JSON.stringify(nv[NameData[0]]['100米'][0]['value']).hasOwnProperty('100米'));
/*判断项目键名中是否为空或未定义*/
function typeArr(newArr, key) {
  if (typeof(newArr) == 'undefined' ? false : (newArr.length == 0 ? false : true)) {
    return JSON.stringify(nv[NameData[0]][projectData[key]][0]['value']);
  } else {
    return "0";
  }
}


var brr = [];
brr[0] = JSON.stringify(nv[NameData[0]][projectData[0]][0]['value']);
brr[1] = JSON.stringify(nv[NameData[0]][projectData[1]][0]['value']);
brr[2] = typeArr(JSON.stringify(nv[NameData[0]][projectData[2]]), 2);
brr[3] = JSON.stringify(nv[NameData[0]][projectData[3]][0]['value']);


document.write('[' + brr + ']');