if ( <condition> ) {
    <action>
}

if( 10 > 5 ) {
    alert("10 is greater than 5!")
}

if( 10 > 50 ) {
    alert("10 is greater than 50!")
} else {
    alert("10 is not greater than 50!")
}

if( 10 > 50 ) {
    alert("10 is greater than 50!")
} else if (10 > 25) {
    alert("10 is not greater than 50, but it is greater than 30!")
} else {
    alert("10 is not greater than 50 nor 30!")
}

let age = 14;

if(age > 18) {
    alert("You're an adult");
} else if (age < 18 && age > 12) {
    alert("You're a teenager");
} else {
    alert("You're a child");
}
// This would output "You're a teenager", because 12 is smaller than 18 and bigger than 12.  

let age = 58;
let money = 1000;

if(age > 60 || money > 800) {
    alert("You can enter");
} else {
    alert("Sorry, you're not allowed to enter");
}

// This would output "You can enter", because, even though the age variable is smaller than 60, the money is bigger than 800.

let isFull = false;

while( ! isFull ) {
    eat();
}
// This code will run untill isFull becomes true. Reading it as 'while not isFull' might help understanding it.
// Interpret the eat() part as calling an external function that will set isFull to true whenever it decides to.

• Guess the Number

• Temperature Conversor

• Divisible Numbers