I dont understand the if statement

An if statement checks a condition and if the condition is true, it runs the code.

Conditions can be 'True' or 'False'. We are checking if something is true or not true.

Say we had a variable called Monday.

dayOfTheWeek = Monday

We can use an if statement to see if today is Monday. If it is Monday, we want to do some special code.

// Check if today is Monday. If it is, print out "It's Monday!"
if (dayOfTheWeek == Monday) {
    print("It's Monday!")
}

We can also check for true and false other ways too.

Say we had a number that equaled 5.

int number = 5

We can check to see if the number is greater than 0, which should be 'true'. If it is true, we want to tell the user.

The first if statement will run, because 5 is greater than 0 (true) and the second if statement will not run because 5 is not less than 0 (false).

if(number > 0) {
    print("The number is greater than 0!");
}

if(number < 0) {
    print("The number is less than 0!");
}

I hope that is a little clearer, if it's not, feel free to reply and I can try to explain more or give more examples. It's one of those things where the more you do it, the more you will become better at it.