I am using JavaScript, why can the following code not execute?

Question

var day = prompt("What day is it?","")
if (day == Saturday || day == Sunday)
alert("Enjoy your Weekend")

Answer 1

Prompt returns a string. You need to encapsulate them in quotes (day == "Saturday"). You should also eliminate case-sensitivity by using day.toLowerCase() == "saturday"

What you have done in your code example is ask whether the value of the variable "day" is equal to the value of the variable "Saturday". Obviously since no such variable exists, this is invalid. Literal strings must be enclosed with quotes.

Answer 2

You either need to add statements like this before you code:
var Saturday="Saturday";
var Sunday="Sunday";

or add the quotes to change the if statement to compare to strings instead of variables.
if (day=="Saturday" || day=="Sunday")