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In this lecture you will learn about the default values in C plus plus.

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So variables of a built in types should be initialized before you first use them.

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But there are some situations when the compiler will provide a default value.

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So if you declare a variable at a file scope.

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Uh, or globally in your project and you don't give it an initial value, the compiler will give it

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a default value, for example.

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So let's outside create an outside variable.

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Integer outside and then create an inside variable, for example.

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Or let's increment outside by one and then print f our outside.

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This is the integer manager integer.

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So we will we're going to use the decimal format specifier here and then pass our outside as an argument

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and let's compile our application and see what happens.

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As you can see here, we got the one.

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So.

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The code will compile and run and it printed the value one so the compiler has initialized the outside

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to zero.

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So when it's incremented to one.

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So actually, let me write this here outside um, zero by default and here incremented increment by

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one.

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Uh, by plus one.

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Plus one.

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And here, um, output here, one here.

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And let's create another example here, which called inside.

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So create an inside, inside actually integer inside.

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It's going to be an integer type inside and do not assign anything on it.

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And let's increment inside by one plus plus here and let's print the inside variable.

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Actually, let's mention here inside of this is an outside one outside and then print the inside one

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here.

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Print f, okay.

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Inside.

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Yes.

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And here pass insight as an argument here.

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Parameter here and then.

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Let's compile and run our application.

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So as you can.

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I'm sorry.

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I have to add the new line here.

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We don't have to add to the last line, but it's okay.

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So let's add it just in case.

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As you can see, inside, one outside one.

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So.

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And here the compiler will compile and the increment operator is being used as a uninitialized variable.

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So in the last lecture we have another example of the compiler providing the default value static.

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So here, let's create an example here.

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Um, static integer count here, for example, return.

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Uh, here we're just going to be here.

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Return plus plus, count here count.

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So as you can see here, actually it's let's instead of writing like this, let's create another count

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function so we don't mess with the main function here and call our count function whenever we want.

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And then let's add here our integer count function.

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Uh, then static.

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Let's add the static integer count variable here.

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And this counter, as you can see here, this function returns an integer.

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So we're going to return the integer.

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As you can see, count is integer, count variable is integer.

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So it's in order to more understandable.

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So let's like write like variable type.

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So here, plus plus count.

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You will see.

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Actually, my count.

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Plus.

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Plus my count.

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My count.

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So this is a simple function that maintains a count.

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So the variable count here, my count is marked with the static search class modifier, meaning that

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the variable has the same lifetime as the application so located when?

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So this allocated when the code starts and they are located when the program ends.

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So however it has an internal linkage.

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So meaning the variable can only be used within the scope of where it is declared.

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So the counter function.

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So the compiler will initialize the count my count variable with a default value of zero.

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And then so that the first time counter function is called, it will return the value zero.

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So, so, so.

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But it will return the value one.

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I'm sorry, I'm mistaken.

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It will return the value one because we increment it.

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This my count by one returns one returns one here.

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Okay.

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Actually, let's print death count.

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Function.

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From.

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Shown here and the, uh, counter here, uh, past counter and let's see what happens.

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As you can see here, count function gave counter function gave us, returned us one.

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And we have a new initializer list, syntax of C plus plus 11.

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So this is the update upgrade on C plus plus language here.

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So the initial initializer list, syntax of C plus plus 11 provides a way for you.

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Declare a variable and specify that you want it initialized by the compiler to the default value for

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the type.

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So for example, let's create an example variable here, integer A here and then like this.

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So it might be strange, but I will explain all of this.

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So of course when you read this code, it's you have to know that the default value for an integer is

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zero.

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So again, it's much easier, easier and more explicit to simply initialize the variable to a value.

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E equals equals zero.

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Here, of course it's more easy, but the rules for the default values are simple.

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A value of zero.

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So integers and floating point numbers have a default value of zero for a character.

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The default value is.

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Let me show here like this.

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This is the zero.

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So for a bool is false and for a pointer is the constant nullptr here.

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So this is the also zero.

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I want to here mention here and here.

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Char default value is our default value is here.

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Parentheses slash zero boolean bool default value is false and the floating point number is same as

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the integer.

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It is zero.

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And let me mention it for pointer.

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It's a pointer.

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Pointer is default, value is nullptr, which I will explain what nullptr is.

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So in next lecture we're going to learn the declarations with without a type.

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So I'm waiting you in next lecture.