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JavaScript Quickstart

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Get Information From a Function

2:52 with Guil Hernandez

Just like you're able to pass information to a function, you can get information back from a function when it finishes running the code inside the curly braces.

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Practice working with Functions in JavaScript

In this short workshop, you'll practice creating basic JavaScript functions, adding parameters, calling functions and passing values.

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    Just like you're able to pass information to a function, you can get information 0:00
    back from a function when it finishes running the code inside the curly braces. 0:04
    So now, I'll create a new function called 0:08
    add that will add two numbers together and return the total. 0:13
    Functions can accept multiple perimeters, so I'll have this function 0:18
    take two parameters, separated by a comma, I'll name them a and b. 0:23
    Now to return a value from a function you use the return keyword. 0:28
    This creates a return statement that specifies the value to return. 0:34
    So I'll have this function return the sum of a plus b. 0:38
    Creating a function that returns a value makes the function flexible enough that 0:45
    you can use it in many different situations. 0:49
    So for example, this time I'll output the value the add function returns to 0:52
    the browser console using console.log. 0:56
    And console.log works similar to alert and prompt. 1:01
    You put something inside the parentheses and 1:04
    it's displayed and/or printed to the browser console. 1:06
    So for example, I'll pass console.log, a call to the add function, 1:09
    and then I'll pass add to arguments 20 and 30, separated by a comma. 1:15
    And right below, let's call add inside a second console.log. 1:21
    This time I'll pass add the arguments 120 and 310. 1:27
    You'll use console.log frequently while programming. 1:34
    As you'll see later, console.log comes in handy when trying to figure out what's 1:39
    going on inside a program. 1:42
    You can use it to print messages as your program's run and help debug your code. 1:44
    So in this case, the return value is given to each add function call. 1:49
    So over in the browser, you'll see the numbers 50 and 1:55
    430 get logged to the console. 1:59
    And you could also, for example, make this a function that multiplies two values and 2:02
    returns the result. 2:07
    So I will change add to multiply, and 2:08
    I will return a * b using the asterisks symbol, 2:12
    and the console let's call multiply once, 2:17
    inside a console.log and I will pass it the arguments,6 and 2:22
    8, give that a save, refresh, and this logs the number 48. 2:28
    JavaScript functions are a valuable tool in your programming toolkit. 2:35
    Functions can let you run a dozen or 2:39
    hundreds of lines of programming by typing just a single line of code. 2:41
    You'll use them constantly in your JavaScript programs 2:46
    to make your programs more modular and easier to update. 2:49

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