# Understand the concept of useState() in ReactJs

The useState Hook in ReactJs allows you to implement the state variable without using a class-based component. 

First, to use the useState Hook, you import it from 'react'
```
import { useState } from 'react
``` 
The useState function takes two arguments; an initial state and it returns an array of two entries (the *current state* and the function that *updates* the state).
```
 const [count, setCount] = useState(0);
``` 

```
import {useState} from 'react'

function NumberChange() {
 const [count, setCount] = useState(0);
}
``` 
from the code above, the ```count```  is the current state while the ```setCount``` function is used to update our state. 

We then set our initial state to zero ```useState(0)```

Let us look at an example. We will change the number from its initial value of zero (0) to another value. 


```
import { useState } from "react";

function NumberChange() {
  const [count, setCount] = useState(0);

  return <h1>The First Number is  {count}</h1>
}
```

Now, let's update the state

```
import { useState } from 'react'

function NumberChange() {
 const[count, setCount] = useState(0);

return(
    <div>
             <h1>The First Number is  {count}</h1>
             <button onClick = {() => 
                    setCount(1);
                }></button>
    </div>
)

}
```