JSFiddle - React, Tailwind, and code Playground

HTML

<button onClick="getFiles()">click</button>

JavaScript

var jsonStr = {
    "hierarchy": {
        "date": "2014/09/24 15:21:23",
        "folder": {
            "name": "Root",
            "id": "Root",
            "file": [{
                "id": "22U2621210__PIN_検査報告書Ver1.0_20140923162232.xls"
            }, {
                "id": "C22-1(EU仕様)_20140923162409.xlsx"
            }, {
                "id": "Machine_Inspection_20140923162329.xlsx"
            }],
            "folder": {
                "name": "Level-1",
                "id": "1411396172645",
                "file": {
                    "id": "22U2621210__PIN_検査報告書Ver1.0_20140923162232.xls"
                },
                "folder": {
                    "name": "123",
                    "id": "1411538469568",
                    "file": [{
                        "id": "C22-1(EU仕様)_20140923162409.xlsx"
                    }, {
                        "id": "Machine_Inspection_20140923162329.xlsx"
                    }]
                }
            }
        }
    }
};
var id = "1411396172645";


    alert(jsonStr.folder.id);