Introduction to React Hook Form: How to submit a form with handleSubmit without using useState

Introduction

When writing forms in React, many people initially combine useState and onChange to manage input values.
However, using React Hook Forms actually makes these unnecessary.
Here, we'll explain why useState is unnecessary and the role of handleSubmit / onSubmit.

Problem

Common form syntax:

const [userId, setUserId] = useState("");

<input value={userId} onChange={(e) => setUserId(e.target.value)} />

• Input management using useState and onChange is time-consuming.

Solution

In RHF, register already manages input values.
Therefore, useState and onChange are unnecessary.

const onSubmit = (data: any) => {
navigate(`/cards/${data.userId}`);
};

<form onSubmit={handleSubmit(onSubmit)}>
<input {...register("userId")} placeholder="Enter ID" />
<button type="submit">Submit</button>
</form>

Key Points

• register("userId") → React Hook Form automatically manages state.

• handleSubmit(onSubmit) → Collects input values ​​and passes them to data.

• onSubmit → Processing upon submission (in this case, navigate to the next page).

This neatly unifies "input management" and "submission processing"!