1.4 - Conditionals
Review
We now have the ability to write code that takes input (prompt), processes it (math), and gives output (console.log)
We know the difference between a number and a String
We have learned some Math and String functions that can be really helpful
1.4 - Conditionals
How do we make decisions based on information?
Friend: "Want to go to the movies?"
You: "Only if you pay."
What happens if your friend pays? What else could happen?
Consider a program that determines if a number is even or odd.
Ask the user for a number (or get a random one).
⤷ What if they enter a word instead?
Let's say it's a number...
⤷ How do we decide if it's even?
Interesting Notes & Resources:
There is an operator that determines the remainder of a division statement.
% or "Modulo"
Examples: 8 % 3 returns 2, or 9 % 5 returns 4, and 16 % 4 returns 0
How could that be used to determine if a number is even or odd?
The internet is full of tutorials, more tutorials, and examples about the if-else statement since it is one of the very first constructs people learn in programming.
Extras
Here's something weird - try ("A" < "a") or ("A" > "a")
Because the if-else condition is boolean logic, you can combine multiple conditions with AND and OR
AND uses the operator && and OR uses the operator ||
Example:
let x = 5, y = 3;
if ((x < 10) && (y > 1)) {
console.log("Hooray!");
} else {
console.log("Boooo");
}
What will the above code output to the console?