Use a concatenated (dynamic) string as JavaScript object key? [duplicate]

Answer 1

Javascript provides two ways to define a property of an object:

1. object.propertyName = value;

In this situation, the propertyName is un-editable, and un-computable. you cannot do the following:

    object.('property'+'Name')

as you can see

    object = {propertyName:value};
    object = {'propertyName':value};

they are equal

2. you can use a variable as the property name with "[]";

you can do :

 var a  = "propertyName";
 object[a] = value;

and this time you have to use a string

object[propertyName] = value;//error
object["propertyName"] = value;//correct
object = {'propertyName':value};//correct
object = {propertyName:value};//correct