The following code gives error.
var user;
user.load= function () {
//
}
It gives error Cannot read property 'load' of undefined
EDIT: Isn't everything an Object by default in Javascript?
5 Answers
The user variable needs to be an object in order for you to assign properties to it. Variables that have not been assigned a value are undefined, and you can't assign properties to undefined.
var user = {};
user.load = function () {
// ...
}
1 Comment
fvgs
Alternatively, you could do
var user = new Object();try this:
var user = {};
user.load= function () {
//
}
Comments
var user = {
load: function(){
return 'hi';
}
};
user.load();
or
var user = function(){
this.load = function(){
return 'Hi';
}
}
1 Comment
Felix Kling
For the second one to work, you have to create an instance of the constructor function.
Isn't everything an Object by default in Javascript?
No. Many things are objects, but the default value of a variable is undefined, and that is is a primitive which cannot be assigned properties.
You need to assign an object (a new empty object is fine) to the variable:
var user = {};
Cannot set a property ("load") on undefinedundefined(the default value of initialized variables) is a primitive value and doesn't have an object equivalent (like strings for example), so autoboxing doesn't take place.var user = 1; user.load = function(){}would work (you just wouldn't be able to access it later... it's complicated).(1).loadis), then the value is first converted to an object by callingToObjectbefore the reference is resolved.