我以两种不同的方式输出一个对象的长度，它会产生两种不同的反应：
console.log(appData.HomeGateway.questions.length);
console.log(appData.HomeGateway.questions);
输出：
3
0: Object
1: Object
2: Object
3: Object
4: Object
5: Object
6: Object
7: Object
8: Object
length: 9
我知道为什么我会得到两种不同的长度？无论出于何种原因，appData.questions似乎都是从其他对象继承对象。
这是JSON：
var appData = {
"HomeGateway": {
"company": "",
"title": {
"english": "",
"spanish": "",
"russian": "",
"otherlanguage": ""
},
"language": "english",
"pressOKQuestion": {
"left": {
"english": "Press ",
"spansih": "",
"russian": ""
},
"right": {
"english": " to move to the next question",
"spanish": "\" to move to the next question",
"russian": ""
}
},
"pressOKMessage": {
"left": {
"english": "Press ",
"spansih": "",
"russian": ""
},
"right": {
"english": " to move on",
"spanish": "\" to move to the next question",
"russian": ""
}
},
"pressUpDown": {
"left": {
"english": "Please press ",
"spanish": "",
"russian": ""
},
"middle": {
"english": " or ",
"spanish": "",
"russian": ""
},
"right": {
"english": " on your remote control to select",
"spanish": "",
"russian": ""
}
},
"questions": [{
"url": "/question/1",
"question": {
"english": "Have you talked to your doctor today?",
"spanish": "",
"russian": ""
},
"view": "views/question.html",
"controller": "loadData",
"nextPage": "#/question/2",
"answers": [{
"id": 1,
"answer": {
"english": "Yes",
"spanish": "Si",
"russian": ""
}
}, {
"answer": {
"english": "No",
"spanish": "No",
"russian": ""
},
"message": "/message/3"
}]
}, {
"url": "/question/2",
"question": {
"english": "On a scale of 0-10, how bad is your pain today?",
"spanish": "",
"russian": ""
},
"icon": "img/icons/1446585749_Doctor_Consultation.png",
"iconSrc": "Broken Arm",
"view": "views/question.html",
"controller": "loadData",
"nextPage": "#/question/3",
"answers": [{
"answer": {
"english": "Low",
"spanish": "",
"russian": ""
},
"category": "1-2"
}, {
"answer": {
"english": "Medium",
"spanish": "",
"russian": ""
},
"category": "3-4"
}, {
"answer": {
"english": "High",
"spanish": "",
"russian": ""
},
"category": "5-8",
"message": "/message/4"
}, {
"answer": {
"english": "Very High",
"spanish": "",
"russian": ""
},
"category": "9-10",
"message": "/message/4"
}]
}, {
"url": "/question/3",
"question": {
"english": "Please enter your systolic blood pressure.",
"spanish": "",
"russian": ""
},
"icon": "img/icons/1446585795_Blood_Pressure_Kit.png",
"iconSrc": "Blood Pressure",
"view": "views/toggle-question.html",
"controller": "loadData",
"nextPage": "#/finished",
"toggle": {
"value": 100,
"max": 500,
"min": 50,
"high": {
"value": 150,
"message": "/message/5"
},
"low": {
"value": 75,
"message": "/message/6"
}
}
}],
"messages": [{
"url": "/message/1",
"message": {
"english": "Please talk to your nurse or doctor about why you do not want to.",
"spanish": "",
"russian": ""
},
"icon": "img/alert-red.png",
"iconSrc": "Alert",
"view": "views/message.html",
"controller": "loadData",
"nextPage": "#/message/2"
}, {
"url": "/message/2",
"message": {
"english": "Good job!",
"spanish": "",
"russian": ""
},
"icon": "img/icons/1446586860_Best_Choice.png",
"iconSrc": "Thumbs Up!",
"view": "views/message.html",
"controller": "loadData",
"nextPage": "#/question/1"
}, {
"url": "/home",
"title": {
"english": "Thank you for being part of today.",
"spanish": "",
"russian": ""
},
"subtitle": {
"english": "Remember this device does not take place of a personal emergency response system or a call to 911.",
"spanish": "",
"russian": ""
},
"view": "views/home.html",
"controller": "loadData",
"nextPage": "#/question/1"
}]
}
}
注意：只是编辑它以反映我用来获得不同长度的方法。
答案 0 :(得分：1)
没有# Melt to aggregate data
df2 <- melt(df, id = c("id", "year", "month", "element"))
for (i in 1:nrow(df2)) {
df2$date[i] <- paste0(df2$year[i], df2$month[i], substr(df2$variable[i], 2,3))
}
。它必须是appData.questions，在两种情况下都给出三个（当然它确实如此）。以下是您自己数据的演示：
appData.HomeGateway.questions
答案 1 :(得分：1)
我认为你正在第二个console.log中跳过一个键
假设这不是实际的代码，而是为我们编写的，我假设您错过了第二个控制台中的问题键。它可能看起来像这样
import imp
import sys
from threading import Thread
from time import sleep
import wx
class MyFinder(object):
def __init__(self):
print('MyFinder initializing')
if imp.lock_held():
while imp.lock_held():
print('import lock held')
sleep(2)
print('import lock released')
else:
print('import lock is not held')
def find_module(self, module, package=None):
print('MyFinder.find_module called with module name "{}", pakcage name "{}"'.format(module, package))
return None
def test():
sys.meta_path.append(MyFinder())
from my_time import sleep
count = 0
while True:
print("{} thread still running".format(count))
count += 1
sleep(2)
app = wx.App()
frame = wx.Frame(None, -1, 'simple.py')
frame.Show()
thread = Thread(target=test)
thread.setDaemon(True)
thread.start()
app.MainLoop()