json是前后端数据交互的关键。后端提供的接口中的数据几乎都是通过json来表现的，所以，需要对这个json做一些小结；
这里要推进谷歌的插件Fehelp前端助手，这个可以清楚的看到json的数据；
以如下json数据为例
{
"equipments": [
{
"run_status": "1",
"name": "空压机1",
"data": {
"id": "4028817a5c8a9943015caa447ac727f0",
"equipment_id": 1,
"a_electricity": 113,
"shake": 2.5,
"rate": 0,
"temperature1": 66,
"temperature2": 77,
"pressure1": 0,
"pressure2": -13.9,
"pressure3": 0.31,
"air_supply_pressure": 0.31,
"venting_temperature": 77,
"run_time": 15629,
"load_time": 14750,
"main_a_electricity": 0,
"run_status1": "100000000011",
"run_status2": "0",
"control_status": 0,
"oil_filter_used_time": 2941,
"oil_distributor_used_time": 0,
"air_filter_used_time": 0,
"lubricating_oil_used_time": 2941,
"lubricating_grease_used_time": 2941,
"degree": 269208,
"inverter_fault_code": 0,
"remark2": null,
"remark1": 0,
"power": 71,
"link_status": 1,
"date": 1497505233603,
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017
},
"load_status": "1",
"link_status": 1,
"fault": null,
"type": 4,
"equipment_id": 1
},
{
"run_status": "1",
"name": "空压机2",
"data": {
"id": "4028817a5c8a9943015caa447ac827f1",
"equipment_id": 2,
"a_electricity": 115,
"shake": 2.1,
"rate": 88.6,
"temperature1": 62,
"temperature2": 77,
"pressure1": 0.428,
"pressure2": -10.1,
"pressure3": 0.4,
"air_supply_pressure": 0.4,
"venting_temperature": 77,
"run_time": 16060,
"load_time": 15996,
"main_a_electricity": 143,
"run_status1": "100000000011",
"run_status2": "0",
"control_status": 0,
"oil_filter_used_time": 2997,
"oil_distributor_used_time": 312,
"air_filter_used_time": 88,
"lubricating_oil_used_time": 2997,
"lubricating_grease_used_time": 2997,
"degree": 200835,
"inverter_fault_code": 13,
"remark2": null,
"remark1": 0,
"power": 72,
"link_status": 1,
"date": 1497505233603,
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017
},
"load_status": "1",
"link_status": 1,
"fault": {
"id": "4028817a5c8a9943015c948cd2734d2f",
"type": 1,
"has_read": null,
"date": "2017-06-11 08:27:55",
"equipment_id": 2,
"info": "空压机2:[报警]"
},
"type": 4,
"equipment_id": 2
},
{
"run_status": "1",
"name": "空压机3",
"data": {
"id": "4028817a5c8a9943015caa447ac927f2",
"equipment_id": 3,
"a_electricity": 70,
"shake": 0.6,
"rate": 17.8,
"temperature1": 38,
"temperature2": 78,
"pressure1": 0.32,
"pressure2": -2.6,
"pressure3": 0.308,
"air_supply_pressure": 0.308,
"venting_temperature": 78,
"run_time": 6751,
"load_time": 6733,
"main_a_electricity": 174,
"run_status1": "11",
"run_status2": "0",
"control_status": 0,
"oil_filter_used_time": 0,
"oil_distributor_used_time": 137,
"air_filter_used_time": 775,
"lubricating_oil_used_time": 0,
"lubricating_grease_used_time": 0,
"degree": 376393,
"inverter_fault_code": -23017,
"remark2": null,
"remark1": 0,
"power": 43,
"link_status": 1,
"date": 1497505233603,
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017
},
"load_status": "1",
"link_status": 1,
"fault": {
"id": "4028817a5ba84088015bb2f9496059a7",
"type": 1,
"has_read": null,
"date": "2017-04-28 13:12:13",
"equipment_id": 3,
"info": "空压机3:[主电机电流故障, 报警]"
},
"type": 4,
"equipment_id": 3
},
{
"run_status": "1",
"name": "空压机4",
"data": {
"id": "4028817a5c8a9943015caa447acb27f3",
"equipment_id": 4,
"a_electricity": 68,
"shake": 2.5,
"rate": 44.8,
"temperature1": 66,
"temperature2": 68,
"pressure1": 0.429,
"pressure2": -4.1,
"pressure3": 0.41,
"air_supply_pressure": 0.41,
"venting_temperature": 68,
"run_time": 16551,
"load_time": 16542,
"main_a_electricity": 120,
"run_status1": "100000000011",
"run_status2": "0",
"control_status": 0,
"oil_filter_used_time": 3065,
"oil_distributor_used_time": 182,
"air_filter_used_time": 100,
"lubricating_oil_used_time": 3065,
"lubricating_grease_used_time": 3065,
"degree": 186991,
"inverter_fault_code": 22,
"remark2": null,
"remark1": 0,
"power": 38,
"link_status": 1,
"date": 1497505233603,
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017
},
"load_status": "1",
"link_status": 1,
"fault": null,
"type": 4,
"equipment_id": 4
},
{
"run_status": "0",
"name": "空压机5",
"data": {
"id": "4028817a5c8a9943015caa447acc27f4",
"equipment_id": 5,
"a_electricity": 0,
"shake": 0,
"rate": 0,
"temperature1": 0,
"temperature2": 0,
"pressure1": 0.409,
"pressure2": -100,
"pressure3": 0,
"air_supply_pressure": 0,
"venting_temperature": 0,
"run_time": 601,
"load_time": 0,
"main_a_electricity": 0,
"run_status1": "0",
"run_status2": "0",
"control_status": 0,
"oil_filter_used_time": 601,
"oil_distributor_used_time": 601,
"air_filter_used_time": 601,
"lubricating_oil_used_time": 601,
"lubricating_grease_used_time": 601,
"degree": 0,
"inverter_fault_code": 0,
"remark2": null,
"remark1": 0,
"power": 0,
"link_status": 1,
"date": 1497505233603,
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017
},
"load_status": "0",
"link_status": 1,
"fault": null,
"type": 4,
"equipment_id": 5
},
{
"name": "冷干机1",
"data": {
"id": 4852493,
"equipment_id": 6,
"m0": 50,
"m1": 6.4,
"m2": 135,
"m3": 150,
"m4": 20,
"m5": 2,
"m6": 1,
"m7": 0,
"m8": 0,
"m9": 0,
"m10": 0,
"m11": 13.37,
"m12": 0,
"m13": 0,
"m14": 0,
"m15": 0,
"m16": 0,
"m17": 0,
"m18": 0,
"m19": 15,
"m20": 0,
"m21": 0,
"power": 3,
"degree": 10840,
"electricity": 6,
"link_status": 1,
"date": 1497505233603,
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017
},
"fault": null,
"type": 6,
"equipment_id": 6
},
{
"name": "冷干机2",
"data": {
"id": 4852494,
"equipment_id": 7,
"m0": 40,
"m1": 15.1,
"m2": 135,
"m3": 189,
"m4": 20,
"m5": 2,
"m6": 1,
"m7": 0,
"m8": 0,
"m9": 0,
"m10": 0,
"m11": 12.4,
"m12": 0,
"m13": 0,
"m14": 0,
"m15": 0,
"m16": 0,
"m17": 0.297,
"m18": 0,
"m19": 20,
"m20": 0,
"m21": 0,
"power": 3,
"degree": 17258,
"electricity": 11,
"link_status": 1,
"date": 1497505233603,
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017
},
"fault": null,
"type": 6,
"equipment_id": 7
},
{
"name": "流量计1",
"data": {
"id": "4028817a5c8a9943015caa447acd27f5",
"equipment_id": 8,
"dew_point": -20,
"real_time_flow": 1286,
"workshop_pressure": 0.423,
"flow": 10772462,
"iquid_level1": 0,
"iquid_level2": 0,
"iquid_level3": 0,
"iquid_level4": 0,
"il_status": 0,
"il_alert": 0,
"link_status": 1,
"date": 1497505233603,
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017
},
"fault": null,
"type": 11,
"equipment_id": 8
},
{
"name": "流量计2",
"data": {
"id": "4028817a5c8a9943015caa447ace27f6",
"equipment_id": 9,
"dew_point": -20,
"real_time_flow": 1315,
"workshop_pressure": 0.304,
"flow": 12162422,
"iquid_level1": 0,
"iquid_level2": 0,
"iquid_level3": 0,
"iquid_level4": 0,
"il_status": 0,
"il_alert": 0,
"link_status": 1,
"date": 1497505233603,
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017
},
"fault": null,
"type": 11,
"equipment_id": 9
},
{
"name": "联控箱",
"data": {
"id": 2426247,
"date": 1497505233603,
"jc_pressure": 0.31,
"jc_load_pressure": 0.001,
"jc_unload_pressure": 0.001,
"jc_rate": 0,
"jc_status": 0,
"link_status": "1111100000",
"run_status": "11110",
"load_status": "11110",
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017,
"equipment_id": 10,
"electricity": 366
},
"fault": null,
"type": 12,
"equipment_id": 10
}
],
"rooms": [
{
"bgl": 9.02,
"name": "空压机房",
"data": {
"id": "4028817a5c8a9943015caa447ad427f9",
"room_id": 1,
"degree": 1061525,
"electricity": 383,
"power": 230,
"flow": 22934884,
"real_time_flow": 2601,
"date": 1497505233603,
"hour": 2017061513,
"day": 20170615,
"month": 201706,
"year": 2017,
"temperature": null,
"humidity": null
}
},
{
"bgl": 0,
"name": "01号配电房",
"data": null
},
{
"bgl": 0,
"name": "02号配电房",
"data": null
}
]
}
这个json数据中包含equipments和rooms两个数组，ajax接受这个json数据之后需要通过JSON.parse方法转换为对象，这样就能访问里面的数据了。然后JSON.parse(data).equipments['i']便可以访问数组里面的数据了。这个数字里面又是对象，可以继续通过'.'语法调用里面的数据；
浏览器端一般情况下，我们可以使用 JSON.parse() 方法将json数据转换为 JavaScript 对象来渲染数据到页面上；
服务器端我们通常可通过JSON.stringify(obj)将对象装换为字符串来使用