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+Now let's look at how we can do debugging within
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+2
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+Eclipse. I created a new file called AddNumbers which I'm
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+3
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+showing here. It takes two numbers, parses them into integers,
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+4
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+adds them and prints the sum, supposedly, of the two numbers.
+
+5
+00:00:14,870 --> 00:00:17,450
+Now we look at the run configuration for this program,
+
+6
+00:00:17,450 --> 00:00:19,670
+and here you can see that we're passing two arguments,
+
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+two and five, to the program. So now let's run
+
+8
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+our program and see what happens. And the result says that
+
+9
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+2 plus 5 is equal to 10, which is not
+
+10
+00:00:28,150 --> 00:00:31,030
+exactly correct. So we need to debug our program. We
+
+11
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+need to figure out what's wrong with the program, why
+
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+the wrong result was, produced. So we're going to add a break
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+13
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+point here by double-clicking here on the side of the
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+code. And the break point is basically a place where I'm
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+15
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+telling my debugger to stop during the execution because I
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+want to inspect the state of the program. So to start
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+17
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+debugging, we select Debug as Java Application from the Context
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+menu, similar to what we were doing for running the program.
+
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+And as you can see, this asks us whether we want
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+to pass to the debug perspective, which is a, a perspective
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+specifically designed for debugging. We say yes. And as you
+
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+see here, it shows us, it's like a different, set of
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+views, so we can see the code down here with an
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+indication of where the execution is. And of course the execution
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+stopped at the break point, which is exactly where
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+we told the debugger to stop. So let's look at
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+some of the other views in this perspective. The view
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+here on the right-hand side, for example, shows the variables
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+in scope and the break points that are currently active
+
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+for the debugging session. This is where the editor is
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+at. The outline of the program and the console at
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+the bottom. So now let's execute one line by clicking
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+on the Step Over button here at the top, and this will
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+execute the line that is currently highlighted and therefore it will move to
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+the next line. And as you can see, one nice feature is that
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+if I move the mouse over a variable, I can see the value
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+of the variable. And the same thing I can do if I look
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+at the variables windows here on the right. If I click it, it
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+will tell me what is the value of the variable, and in case
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+of more complex variables you can even expand it and get more details.
+
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+So now let's step over another line by clicking again this button,
+
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+and as you can see now we get to the line that
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+is actually performing the sum, supposedly, so now let's do the same
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+thing that we did before, and let's mouse over b, and we can
+
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+see that the value of b is five, as expected. So now
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+let's step over this line as well, and execute the actual sum. And
+
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+doing the mouseover thing, we can see that the value of sum
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+is ten, which is not right, of course. In fact, if we check
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+a gain we can see that value of A is two. The
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+value of B is five and therefore it's clear that there's something
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+wrong going on here, and at this point we can notice that
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+here we are doing multiplication instead
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+of addition. And therefore that's what the
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+error is. And this is clearly a very simple case. Right? A
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+case in which probably you just needed to look at the code and
+
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+you didn't need the debugger. But you probably got the idea right?
+
+57
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+So this can be extremely useful when you're debugging, when you're studying more
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+complex programs. If you want to stop the debugger because you're
+
+59
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+done with your debugging session as in this case, you can
+
+60
+00:03:04,557 --> 00:03:07,518
+either click here on the Terminate button or you can also
+
+61
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+just simply tell the debugger to continue the execution, to resume
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+the execution until the program terminates naturally. So, in this case,
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+we're going to click here just to show what happens. And what
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+happens is that, you know, the execution will just continue until
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+the program exits. So now let's say that we want to fix
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+this problem that we just discovered. So we replace the multiplication
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+with an addition, we save the program, and we execute the
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+program again by clicking on this button. And at this point,
+
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+unsurprisingly, we get the right result as shown in the console.