I have a js object like:
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.
Thank you in advance.
5 Answers
You can access the properties of javascript object using the index i.e.
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/
Comments
In Javascript, obj.name is equivalent to obj['name'], which adds the necessary indirection.
In your example:
var fieldName = 'name'
var obj = {
name: 'js',
age: 20
};
var value = obj[fieldName]; // 'js'
Comments
Not related at all, but for anyone trying to define object's field name from a string variable, you could try with:
const field = 'asdf'
const obj = {[field]: 123}
document.body.innerHTML = obj.asdf
1 Comment
draysams
Nice solution!!
It's quite simple, to access an object's value via a variable, you use square brackets:
var property = 'name';
var obj = {name: 'js'};
alert(obj[property]); // pops 'js'
Comments
As objects are associative arrays in javascript you can access the 'name' field as obj['name'] or obj[fieldName] where fieldName = 'name'.
answered Jan 30, 2011 at 5:07
Vitalii Fedorenko
115k29 gold badges152 silver badges111 bronze badges
obj.nameor am I missing the point of the question?obj.<[evaluate_var]>where<[evaluate_var]>is stored as 'name'?