output problem:

Question

var day = prompt("Enter any number:");
switch (day) {
case 1:
document.write("Monday");
break;
case 2:
document.write("Tuesday");
break;
case 3:
document.write("Wednesday");
break;
case 4:
document.write("Thrusday");
break;
case 5:
document.write("Friday");
break;
case 6:
document.write("Saturday:");
break;
default:
document.write("Sunday");
break;
}

Answer 1

prompt return a string not integer or float
try this
var day = prompt("Enter any number:");
switch (day) {
case "1":
document.write("Monday");
break;
case "2":
document.write("Tuesday");
break;
case "3":
document.write("Wednesday");
break;
case "4":
document.write("Thrusday");
break;
case "5":
document.write("Friday");
break;
case "6":
document.write("Saturday:");
break;
default:
document.write("Sunday");
}

Answer 2

you have to convert the value from string to int try with this code before using switch:
day = +day

Answer 3

change the numbers of case to:
case '1'
case '2'
etcetera
because var is a String by default

Answer 4

Thanks