Uncaught TypeError: Cannot read property of undefined
Accessing an Undefined Variable
In this example, person is declared but not assigned a value, so attempting to access the name property of an undefined object results in the error.
Accessing a Property of an Undefined Object
Here, the user object exists, but the age property has not been defined. Trying to access an undefined property leads to the error.
Accessing a Property of a Nested Undefined Object
In this case, the company object exists, but the location object and its city property are not defined, resulting in the error.
How to Handle the Error
To avoid the "Cannot read property of undefined" error, ensure that the objects you're accessing are properly defined and initialized. You can use conditional checks to handle situations where an object might be undefined.
In this example, we check if person exists and has the age property before trying to access it. This prevents the error and allows you to handle the situation elegantly.
You can handle undefined by using if statement.
Also, undefined is of the type undefined:
Moreover, declare a variable then assign undefined to it:
The "Cannot read property of undefined" error occurs when you attempt to interact with properties or methods of objects that are not defined. Properly initializing and checking objects before accessing their properties can help avoid this error.