[英]Javascript Object Property Console.log
I have a javascript object: 我有一个JavaScript对象:
[{ id: 11,
username: 'me',
firstname: 'my',
lastname: 'name',
}]
I'm trying to get the value of the firstname
property, but I can't seem to do it. 我正在尝试获取
firstname
属性的值,但是我似乎做不到。 I thought I knew how to work with objects until this. 我以为我知道在此之前如何使用对象。 I'm developing this within Node.js, which I don't think matters, but I'm new to node, so who knows.
我正在Node.js中开发此代码,我认为这并不重要,但是我是Node的新手,所以谁知道。
Console.log reads the following for my different attempts: Console.log为我的不同尝试读取以下内容:
console.log(typeof(user_info))
= object
console.log(typeof(user_info))
= object
console.log(typeof(user_info[0]))
= object
console.log(typeof(user_info[0]))
= object
console.log(user_info)
= [{ id: 11, username: 'me', firstname: 'my', lastname: 'name', }]
console.log(user_info)
= [{ id: 11, username: 'me', firstname: 'my', lastname: 'name', }]
console.log(user_info[0].firstname)
= TypeError: Cannot read property 'firstname' of undefined
console.log(user_info[0].firstname)
= TypeError: Cannot read property 'firstname' of undefined
console.log(user_info[0]['firstname'])
= TypeError: Cannot read property 'firstname' of undefined
console.log(user_info[0]['firstname'])
= TypeError: Cannot read property 'firstname' of undefined
console.log(user_info['firstname'])
= undefinded
console.log(user_info['firstname'])
= undefinded
console.log(user_info.firstname)
= undefinded
console.log(user_info.firstname)
= undefinded
var output = '';
for(var prop in user_info){
output += prop + ': ' + user_info[prop] + '; ';
}
console.log(output);
= =
0:[object Object];
for(var prop in user_info[0]){
console.log(user_info[0][prop]);
}
= =
11
me
my
name
I feel like I'm so close with the last shot, but I can't wrap my mind around how to get the key while using the for in
loop. 我觉得我与最后一枪非常接近,但是我无法确定如何在使用
for in
循环时获取密钥。 What am I missing? 我想念什么?
**I'm using Firefox, if that helps. **如果您有帮助,我正在使用Firefox。 And though I like Chrome, in the current setting, I'm unable to use Chrome*
尽管我喜欢Chrome,但在当前设置下,我无法使用Chrome *
for(var prop in user_info[0]){
console.log('key = ', prop);
console.log('value = ', user_info[0][prop]);
}
prop - key what you need 支柱- 关键你需要什么
You want key in for... in
? 您想输入
for... in
吗?
How about this... 这个怎么样...
for(var prop in user_info[0]){
console.log(prop);
}
FWIW: console.log(user_info[0]['firstname'])
prints 'my'
in chrome. FWIW:
console.log(user_info[0]['firstname'])
在chrome中显示'my'
。
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