How to avoid "Cannot read property 'name' of undefined" in JavaScript
#7 · 2017-01-17 (updated 2020-01-04) · JavaScript, TypeScriptJavaScript objects may have properties.
If you are trying to access a property that does not exists, you will just get undefined back.
And if you try to get a property of an undefined value, you will get an error message.
var obj = {};
obj.hello; // Evaluates to `undefined`
obj.hello.world; // Uncaught TypeError: Cannot read property 'world' of undefined
ES2020 introduced a new feature called optional chaining to avoid that.
You can use it by replacing . with ?. as in obj.hello?.world.
The optional chaining operator ensures that this expression does not throw an exception but just returns undefined.
Note that TypeScript introduced support for optional chaining in version 3.7.
More information about optional chaining can be found in the following links.