verify nan code example
Example: check if var is NaN
let b=1
let n=readline()
if(isNaN(b)){
console.log("You typed 0!")
}else{
console.log("You did not type 0!")
}let b=1
let n=readline()
if(isNaN(b)){
console.log("You typed 0!")
}else{
console.log("You did not type 0!")
}