To start working with Zod in React, you need to know how to define schemas for your data. Zod provides a simple and intuitive API for describing the shape and type of your data using schema methods. The most common methods you will use are string(), number(), and object(). These methods allow you to define schemas for primitive values like strings and numbers, as well as for more complex objects.

Begin by creating a schema for a string value. You can use the string() method to specify that a value must be a string. For example, if you want to validate a user's name as a string, you would write:

import { z } from "zod";

const nameSchema = z.string();

This schema ensures that any value passed to it must be a string. If you try to validate a number or any other type, Zod will throw a validation error.

Next, you might want to validate a number, such as a user's age. The number() method is used for this purpose:

const ageSchema = z.number();

This schema will only accept numeric values. If you try to validate a string, boolean, or any non-number, it will fail validation.

For more complex data, such as an object representing a user, you can use the object() method. This method takes an object as its argument, where each property is defined by its own schema. For instance, to validate an object with a name (string) and age (number), you would write:

const userSchema = z.object({
  name: z.string(),
  age: z.number(),
});

This schema checks that the input is an object with both a name property (which must be a string) and an age property (which must be a number). If either property is missing or has the wrong type, validation will fail.

The string(), number(), and object() methods are the foundation of Zod schema definitions. Use string() when you need to validate plain text, number() for numeric values, and object() when you want to validate objects with specific keys and value types. As you build more complex forms and data structures, you will combine these methods to describe exactly what your data should look like.