How is "songs" influencing the var playList?

Hi ramseydennis

You've got it right that this is the important bit:

printSongs(playList);

The variable playList holds an array of values. In other words, it stores DATA that we want to access in the function printSongs. When you call the function with this line -- printSongs(playList) -- you're passing the array of songs to the function printSongs(). In the function, that array is then stored in a variable (called a parameter in this case) named songs. That's what happens here

function printSongs( songs ) {

}

When the function runs, that songs variable holds the array -- basically the data in the playList variable. Hope that helps.

I just want to make sure I'm understanding this correctly. So...

• Functions are meant to be reusable with different datasets (and therefore variables)
• To use them with different variables, you have to put a placeholder variable in the function so that the structure is correct
• When the function is called, it is passed an argument (AKA a variable) that will replace the placeholder
• The function runs, it uses the variable that was passed to it and all the information in that variable
• The placeholder variable doesn't do anything else in the program

Is that correct?

I am going to go out on a limb and say that printSongs function is being invoked with playlist as an argument. Something like this :

printSongs(playList);

//When that function gets called songs parameter will have the value of playlist

When defining a function the words you put in the parenthesis are just parameters, like placeholders.

since playList was the array being passed in when the function was invoked it now will be assigned where ever songs was.

Songs is just a placeholder. If you use or call the function like so: printSongs(playList); Then the function is executed with the variable "playList", and the array or information it contains, replacing songs in the code of the function.