REACT JS – Firebase: Data type NUMBER

Simple and quick question (And yes I google it first, got mislead to phone number verification and other stuff), Anyways! back to the point

Why when I input data and I send it to the database it stores everything as a string even though I have set up the type of that input as a ‘number’

Snip of code example

//some code that makes sense (and is working so far except for the data type)

                docRef.set({
                    precio: precio
            })

//Some more code that makes sense as well


<input onChange = {(e) => {setPrecio(e.target.value);}}
     type = 'number'
     pattern = "[0-9]*"
     required
     placeholder="Precio"
 />

So basically I send some data to the firebase and it does make a collection if there’s none and a document with the data i’m sending, now the issue is that the data is being set up as string and I want it as a number so I can use that value later to do some smart maths I guess.

enter image description here

Full code of the important bits

//Relevant variable
const [precio, setPrecio] = useState("");

// Sending all the data I have gathered to the database 
const register = (e) => {
        e.preventDefault();

        const docId = `${grado} | ${descripcion}`;
        const docRef = db.collection('libros').doc(docId);
        console.log(typeof precio)
        docRef.get().then((doc) => {

            if (doc.exists) 
            {
                window.alert("Ya existe ese libro")
            }
            else {

                docRef.set({
                    materia: materia,
                    descripcion: descripcion,
                    editorial: editorial,
                    grado: grado,
                    precio: precio,
                    id: docRef.id

            }).then((r) => {
                window.alert("Libro agregado")
            })}
    })
}

//The bad boy number that still wants to get printed as a string

<div className = "CrearE_row">
                    <input 
                    onChange = {(e) => {setPrecio(e.target.valueAsNumber);}}
                    
                    type = 'number'
                    pattern = "[0-9]*"
                    required
                    placeholder="Precio"
                    />
                </div>

Answer

It is most probably because you are actually sending data that is of type String, even if they only content numbers. This is quite classical when you input data via an HTML form.

You can check that with the typeof operator, as follows:

console.log(typeof precio);
docRef.set({
   precio: precio
})

The console will probably print “string”. You therefore need to convert the value of precio to a number, for example with parseInt(), parseFloat() or Number().


You can see with the following code that if you pass a number, it is correctly saved in the DB.

const precio = 1234;   // We declare a number
console.log(typeof precio);
docRef.set({
   precio: precio
})

Addendum:

As explained in this SO answer you could also use e.target.valueAsNumber instead of e.target.value.