TS1118: An object literal cannot have multiple get/set accessors with the same name

TypeScript is a powerful, typed superset of JavaScript that enables developers to write more robust and maintainable code. The primary feature of TypeScript is its use of types, which are labels used to understand the kind of data a variable can hold. By providing types, developers can catch errors during development rather than at runtime, leading to fewer bugs and a smoother coding experience. If you want to dive deeper into TypeScript and learn to code using AI tools like gpteach, I recommend you subscribe/follow/join my blog for more insights and resources.

One of the essential concepts in TypeScript is the idea of interfaces. An interface is a structure that defines a contract in our code. It specifies properties and methods that an object must have. This is vital in TypeScript, as it allows for improved code organization and type safety, ensuring that objects adhere to defined structures.

TS1118: An object literal cannot have multiple get/set accessors with the same name

Now, let’s discuss TS1118: An object literal cannot have multiple get/set accessors with the same name. This TypeScript error occurs when you define an object literal that includes more than one getter or setter for the same property.

Here’s a basic example to illustrate this:

const obj = {
    get name() {
        return "Alice";
    },
    get name() { // Error: TS1118
        return "Bob";
    }
};

In the example above, the TypeScript compiler throws an error indicating that we cannot have multiple getter accessors named name. This error is coded as TS1118: An object literal cannot have multiple get/set accessors with the same name.

Important to know!

• In TypeScript, each property in an object literal must have a unique name.
• Getters and setters provide a way to define methods for accessing properties, but they should not collide in names.

How to Fix TS1118

To resolve the TS1118 error, ensure that each get/set accessor has a unique name. You can combine the two get accessors or use a different name for one of them. For example:

const obj = {
    get name() {
        return "Alice";
    },
    get alternateName() { // Renamed to avoid conflict
        return "Bob";
    }
};

By changing the second get accessor to alternateName, we no longer have multiple accessors for name, and the error TS1118 is resolved.

More Examples of TS1118

This error can also occur with setters. Here’s how it might manifest:

const obj = {
    _age: 25,
    get age() {
        return this._age;
    },
    set age(value: number) {
        this._age = value;
    },
    set age(value: string) { // Error: TS1118
        this._age = parseInt(value);
    }
};

In the above snippet, attempting to define two setters for age results in the TS1118 error. To fix this:

const obj = {
    _age: 25,
    get age() {
        return this._age;
    },
    set age(value: number) {
        this._age = value;
    },
    set ageFromString(value: string) { // Renamed to avoid conflict
        this._age = parseInt(value);
    }
};

By changing the second setter to ageFromString, we resolve the TS1118 issue.

Important to know!

• When defining object literals, always ensure each accessors’ name is unique.
• Use descriptive names for accessors to avoid conflicts and improve code clarity.

FAQs about TS1118

Q: What happens if I ignore the TS1118 error?
A: Ignoring the error can lead to unintended behavior in your application, as the last defined accessor might overwrite the previous ones resulting in loss of functionality.

Q: Can I use the same name for different objects?
A: Yes, the names of accessors are scoped to the object in which they are defined. You can have the same accessor names in different objects without conflict.

Q: How can I ensure my TypeScript code remains error-free?
A: Use TypeScript’s strict mode features, check for common error patterns, and leverage your IDE’s TypeScript capabilities to catch these issues early.

In conclusion, understanding and adhering to the rules laid out by TypeScript can greatly improve the quality of your code. Different situations might invoke the TS1118: An object literal cannot have multiple get/set accessors with the same name error, but with care and attention to detail, it can easily be avoided. Happy coding!