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Explanation

Optional chaining (?.) safely accesses object properties without throwing an error if the object is undefined or null.

Code:

let user = undefined;
console.log(user?.name);

Explanation

Optional chaining can also be used for nested objects to avoid 'Cannot read properties of undefined' errors.

Code:

let data = {};
console.log(data.user?.profile?.email);

Explanation

You can manually check whether an object is undefined before accessing its properties.

Code:

if(user !== undefined){
    console.log(user.name);
}

Explanation

Using a simple truthy check is a shorter way to verify the object exists.

Code:

if(user){
    console.log(user.name);
}

Explanation

The nullish coalescing operator (??) provides a default value when the result is undefined or null.

Code:

let username = user?.name ?? 'Guest';
console.log(username);

Explanation

Default function parameters help avoid errors when an object argument is not passed.

Code:

function printUser(user = {}){
    console.log(user.name);
}

printUser();

Explanation

Try-catch can handle runtime errors caused by accessing properties of undefined objects.

Code:

try{
    console.log(user.name);
}catch(err){
    console.log('User object is undefined');
}

Explanation

A common modern pattern combines optional chaining and nullish coalescing for safe access with default values.

Code:

console.log(user?.name ?? 'Unknown');