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Hello and welcome to this video.

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What is a default parameter valid.

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This is the value that a function uses when it is called.

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Without passing it a value.

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So when you call a function without a parameter it uses the default value only parameters at the end

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of a parameter list can have a default value.

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This is because the values are assigned by the position.

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So if you have several parameters you can only give the last parameter in the list a default value in

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the first example here.

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Now this is a proper way of assigning a default parameter value because this has two parameter parameter

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a impairment to be because of the way the values are assigned by the position.

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You can only give a default parameter value to the last Parliament inside the function definition.

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So this is the proper way.

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And this one is not the right way because you see him giving it a default value here when he should

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be at the end of the parameter list.

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Let's create a new function.

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So I'm going to create a function called student on the score names and inside the parenthesis I'm going

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to define just one default value.

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So I'm going to call it names names is going gonna be the parameter.

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I'm going to use the equals to sign to assign a value to the parameter.

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I'm going to call it blue line so that is the parameter names.

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And this is the default value.

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So I had my colon and tab and I'll start a new line of code.

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So inside my function body I want to add a print function inside that print function.

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I want the print function to say hello plus the student's name.

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So I.

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Which is to a space and add a addition operator and then add the name of my parameter.

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So my parameter here is called names.

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So what I'm saying once I run this code any values are passed to it.

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It will print out Hello plus whatever name I passed to the function.

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So let's try and call the function and pass it some arguments to call the function you call the function

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by its name which is call student on the score names and then inside the parentheses I can pass in different

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names.

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So let's say for this one I am going to leave it blank.

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I'm just gonna copy this a couple of times.

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So inside the names I'm going to add in some strings because your strings.

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You need to enclose it in quotes.

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So the first one here I'll say John.

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And for this one here I'm going to add Jane right.

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So notice the first one here.

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Line number five.

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I have not passed in any value.

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So what's gonna happen when I execute this code is going to use the default value that I have set inside

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the perimeter here that I defined so let me save my code by pressing control an s. If you are a Mac

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you can do command an s.

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So once you've saved you could play the file.

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So I click on play and you can see the output when I call the function.

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I did not pass in any value for the first student name and it then used the default value which was

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blue line.

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Line 6.

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A pastor named John it says hello John.

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Line 7 passed in the name Jane.

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It says Hello Jane.

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So inside the function body I did say I wanted to print the word hello plus whatever names I have supplied.

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So the names of supplied when I called the function.

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While John again I didn't supply a name for blue line because blue line here is a value the default

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parameter value for these names variable.

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So that's basically how you use parameter default value.

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The key thing to note is that where you have several parameters defined you can only give the default

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value to the last parameter in the list.

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So if you have several parameters you separate them by a comma and you can only add a default value

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to the last one.

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This is because of the positioning.

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Okay.

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The values are signed by position.

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That's it.

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Thank you for watching and bye for now.