 So one of the things that happens when we design and call out a method invoke a method is Please excuse my dear Aunt Sally. So PEMDAS and The first one is parentheses. So if we take a look at this bottom example here some XY What happens is I Evaluate what's inside the parentheses first in this case X X is going to be evaluated And you see that's where what we have here. So this becomes five this seven Becomes or this Y becomes seven those two things occur first and then I Assign it over here So what's going on when I design out a method when I use a method is something called passing by a reference and the idea Behind this is now that when we're working. We're we're looking at something in the sense Let's see. Give me two seconds. Go ahead and fast forward So when we're designing out this code say for example, I've built it out and I do something like index equals one System dot out that print line The value of X Plus X. I'm saying this is what it's going to be Now I'm going to make a second one. I'm going to make a method here called increment X now increment X if we kind of take a look Increment X is a void return data type. So it doesn't need to be stored anywhere So I come down here. I normally put it after my main method or before it really does not matter public static void increment And number again, like I said, I don't care what it was called outside of my method. I Don't care that is called X here inside my method. I'm going to call you number Don't care what you were called. You are number in my world And the same kind of thing I'm going to change this and I'm going to say that this Is now number the reason why is because there is no X inside here Again, it doesn't exist. Oh, well, it exists over here. No, no that exists in this world No X in this one. Notice how I highlight it. I don't see there's an X anywhere. I didn't name it X So I'm just going to call this guy number and This guy number and I'm going to do number plus plus So what happens when I write this code when I run this code? What are the values going to be? What are my outputs going to be and take a look write this code out see what happens? I'll pause for one second Okay, that was hopefully one second probably a little bit more but I pull this out and I bring out my Code so again files I'm going to compile out my test dot Java file Compiled out fine Java test The value of X is one Hopefully, yeah, that's exactly what I was looking at X was one So I printed that out then I go into increment. Well again What happens is anything when I call a method? It activates. I don't move forward in my main method I don't go any further in my main method until this is done So as you can see there's a lot to do the first thing I say is to print the value of number Again, remember I call it number not X So then all of a sudden I say well number plus plus All right, then print it again. Well number was passed by a value meaning only the binary numbers of One were passed on This is because an integer is a primitive data type a A primitive Data type which means it's very small especially in the computer scale of things so I can just Pass it around I can move it wherever I need to I don't have to be too careful with it because things like integer chars Boolean's doubles longs Floats even though they sound big, you know 64 bits 32 bits They're not really big in that grand scheme of how you know how much my processor can handle at one time So I can just throw them wherever So this just magically gets you know the 32-bit notation of one and Then it does whatever it wants to with it and then outside of this it just moves on and as you can see X never actually changed only number