Here's another example of the same pattern:
if (day == "Monday") {
alert("I don't like Mondays");
}
else if (day == "Saturday" || day == "Sunday"){
alert("Hooray, the weekend");
}
else if (day == "Wednesday") {
alert("Some people call this 'hump day'");
}
else if (day == "Friday") {
alert("Weekend tomorrow!");
}
else if (day == "Tuesday" || day = "Thursday") {
alert("Just another day...");
}
else {
alert("Invalid day. Please reboot the universe.");
}
It's simple enough code, just a bit long-winded.
The verbosity of it tends to obscure the big picture "pattern" that there's a thing called "day", and we're going to do a bunch of different things just depending on what it's equal to, and not depending on anything else.