The error "Object is possibly null." occurs when TypeScript's type checker determines that a variable could be null or undefined. This issue can lead to runtime errors, so it's essential to address it properly.

In this article, we'll look at various ways to handle this issue and provide code samples to illustrate each method. Let's get started!

1,  Using the Non-null Assertion Operator (!)

One of the quickest ways to resolve the "Object is possibly null" error is to use the non-null assertion operator (!). This operator tells TypeScript to treat a nullable value as non-null. However, be cautious with this approach, as it can lead to runtime errors if the value is actually null.

// Define a nullable variable
let username: string | null = null;

// Use the non-null assertion operator
console.log(username!.length); // Runtime error: Cannot read property 'length' of null

2,  Using Optional Chaining (?.)

Optional chaining is a safer way to access properties of an object that may be null or undefined. It short-circuits and returns undefined if the object is null, preventing any runtime errors.

// Define a nullable variable
let user: { name: string } | null = null;

// Use optional chaining
console.log(user?.name); // Output: undefined

3,  Using if Statements and Type Guards

Another approach to handling nullable variables is to use an if statement to check if the variable is null or undefined. This method is more explicit and can help you avoid potential errors.

// Define a nullable variable
let age: number | null = null;

// Check for null or undefined
if (age !== null) {
  console.log(age + 1);
} else {
  console.log("Age is null.");

4,  Creating a Custom Type Guard

Type guards are functions that perform runtime checks and narrow down the type of a variable within a specific block of code. You can create custom type guards to ensure a variable is not null before using it.

function isNotNull<T>(value: T | null): value is T {
  return value !== null;

let address: string | null = null;

if (isNotNull(address)) {
} else {
  console.log("Address is null.");

5,  Using the Nullish Coalescing Operator (??)

The nullish coalescing operator (??) returns the right-hand side value if the left-hand side value is null or undefined. This operator can be useful when providing a default value for a nullable variable.

// Define a nullable variable
let countryCode: string | null = null;

// Use nullish coalescing operator
let result = countryCode ?? "Unknown";
console.log(result); // Output: Unknown


In this blog post, we explored various techniques for handling the "TypeScript object is possibly null" error. It's crucial to choose the right method based on your specific use case and requirements. Avoid using the non-null assertion operator if you're uncertain about the variable's value, as it can lead to runtime errors. Instead, consider using safer alternatives like optional chaining, if statements, custom type guards, or the nullish coalescing operator.

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