The user enters a number and determines whether the number is a prime number.
var n = prompt("Please enter a number to help you determine whether it is a prime number");
var count = 0;
for(var j = 1;j <= n; j++){
if(n%j == 0){
count++ ;
}
}
if(count == 2){
alert("This is a prime number");
}else{
alert("This is not a prime number");
}