how to calculate the square of a number code example

Example: square number

const squareNumber = n => {
    let number = ''
    if(n < 0){
        return false
    }else if(n >= 0){
        let square = Math.sqrt(n)
        number = Math.floor(square)
    }
    return number ** 2 === n
}
console.log(squareNumber(0))