What is a Function?

Functions allow you to reuse code

• Performs a specific task
• Begins with the keyword function followed by the function name and parentheses ( )
• Parameters or arguments will be placed inside the parentheses ( )
• Braces { } follow the parentheses ( )
• Your instructions (code block) will be inside of the braces { } 
• The return keyword exits a function
• You must call or invoke the function for it to run the specific task

The Structure of a Function

• Keyword function starts the function
• greeting is the function name
• phrase is the parameter 
• return is the output of the function
• greeting('Aloooooooha') is calling/invoking the function to run the specific task

Parameters and Arguments

• A parameter is a piece of information (a placeholder) that the function needs
• An argument is a piece of information that is passed from a function call into the function

Information that the function needs

Return Values

The value that the function returns

Scope

Access to your variables based on location

• Global variables can be accessed throughout your entire program
• Local variables can be used only inside the function in which they are declared

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