Error when assigning booleans

Question

I started learning Java here yesterday, and I wanted to try to make FizzBuzz in java (https://www.youtube.com/watch?v=QPZ0pIK_wsc). When I assign a boolean and then test it things seem to go fine, but whenever I assign a boolean if another condition is true/false, I get the errors 'cannot find symbol' and 'illegal start of type' for every time I check if the boolean is true.

This is my code:

class SomeClass {
public static void main(String[ ] args) {
for (int i = 1; i <= 100; i++){
if (i % 3 == 0){
boolean multOfThree = true;
}
else{
boolean multOfThree = false;
}
if (i % 5 == 0){
boolean multOfFive = true;
}
else{
boolean multOfFive = false;
}
if (multOfThree){
if (multOfFive){
System.out.println("FizzBuzz");
}
else{
System.out.println("Fizz");
}
}
else{
if (multOfFive){
System.out.println("Buzz");
}
else{
System.out.println(i);
}
}
}
}
}

Answer 1

the problem is thatyou declare boolean inside each if statement. and you need to do it once. it's like you want to put glass inside a glass (same kind of glass). but in fact the only thing you can change is that if glass is empty or not. so declare boolean multOfThree; before first if statement and later use just multOfThree (for example multOfThree = true;) do you get it?

Answer 2

When a variable is declared inside a block of code such as an if statement, the variables scope is within that block. Meaning, it cannot be accessed outside the if statement.

Example:
if (true){
int a = 5;
}
System.out.println(a);
// ERROR, Cannot find symbol 'a'

You are using multOfFive outside its scope.
So, you must enlarge its scope.
Declare the variable outside the if statement like so:

boolean multOfFive = false;
if (i % 5 == 0)
multOfFive = true;
// etc....

/*
Could also write:
boolean multOfFive = (i % 5 == 0);
Now the if statement isn't needed.
*/
Same thing with multOfThree.

While we do want to keep variables in the smallest scope possible, we had good reason to enlarge the scope here. I.E: so we can access it from the other if statements.

Answer 3

Thanks!

Answer 4

https://youtu.be/slq2yAfWUAY