Javascript 如何在javascript中将字符串转换为对象的字段名称
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How to convert string as object's field name in javascript
提问by ywenbo
I have a js object like:
我有一个 js 对象，如：
obj = {
name: 'js',
age: 20
};
now i want to access name field of obj, but i can only get string 'name', so how to convert 'name' to obj's field name, then to get result like obj.name.
现在我想访问obj的name字段，但是我只能得到字符串'name'，那么如何将'name'转换为obj的字段名，然后得到像obj.name这样的结果。
Thank you in advance.
先感谢您。
回答by Chandu
You can access the properties of javascript object using the index i.e.
您可以使用索引访问 javascript 对象的属性，即
var obj = {
name: 'js',
age: 20
};
var isSame = (obj["name"] == obj.name)
alert(isSame);
var nameIndex = "name"; // Now you can use nameIndex as an indexor of obj to get the value of property name.
isSame = (obj[nameIndex] == obj.name)
Check example@ : http://www.jsfiddle.net/W8EAr/
检查示例@：http: //www.jsfiddle.net/W8EAr/
回答by Mathieu Ravaux
In Javascript, obj.nameis equivalent to obj['name'], which adds the necessary indirection.
在 Javascript 中，obj.name相当于obj['name']，增加了必要的间接性。
In your example:
在你的例子中：
var fieldName = 'name'
var obj = {
name: 'js',
age: 20
};
var value = obj[fieldName]; // 'js'
回答by Seldaek
It's quite simple, to access an object's value via a variable, you use square brackets:
很简单，要通过变量访问对象的值，您可以使用方括号：
var property = 'name';
var obj = {name: 'js'};
alert(obj[property]); // pops 'js'
回答by Alter Lagos
Not related at all, but for anyone trying to define object's field name from a string variable, you could try with:
根本不相关，但对于任何试图从字符串变量定义对象的字段名称的人，您可以尝试：
const field = 'asdf'
const obj = {[field]: 123}
document.body.innerHTML = obj.asdf回答by Vitalii Fedorenko
As objects are associative arrays in javascript you can access the 'name' field as obj['name']or obj[fieldName]where fieldName = 'name'.
由于对象是 javascript 中的关联数组，您可以访问 'name' 字段 asobj['name']或obj[fieldName]where fieldName = 'name'。
