Confused about quotations

[frogger44]

Hi,
I'm studying JavaScript and this little bunch of code came up. I'm not understanding how the quotation marks work in this. It's suppopsed to label the ellipse with the mouseX and mouseY coordinates, and it works just fine. I'm just hoping for a new perspective that will help me understand what those quotes mean. Thanks for you help,
Kevin


fill(255, 0, 255);

draw = function() {
background(255, 255, 255);
ellipse(mouseX, mouseY, 12, 12);
var label = mouseX+", "+mouseY;
text(label, mouseX, mouseY);
};

 

[FResher]

var label = mouseX+", "+mouseY;

that is a "String build"

you can create String with surrounding " "

var test_one = "hello " ;

or involve more Strings, and numerics value too

var country_code = 44 ;
var all = "frogger" + country_code ;
var test_two = "hello " + all + "How are you " + "?" ;

the "," in the code is part of the label to display with 2 numeric parameters around the ","
+ is an concatenating operator to build string, and useful to join all parts of a String.

you have 2 numerics value , and they must be separate by "," character.

so the final String to display with name 'label' is made by :
var label = mouseX + "," + mouseY ;
var label contains the string to output with X and Y coordinates of the Mouse

 

[frogger44]

I got it. Thank you so much for helping me understand.

 

[frogger44]

Looking again at the original code. Why does the text not repeat mouseX and mouseY twice? Since the text is the variable label, which is mouseX and mouseY and then is followed again by mouseX and mouseY?

 

[FResher]

when you have :

var label = "you allocate the value IN the var with name 'label'";

text(parameter_1 => text , parameter_2 => X value ,parameter_3 => Y value ) is a function.

MouseX and MouseY are used to give the 'location' of the label to display.

 

[frogger44]

Okay, thank you. I think I see. The 'what' and the 'where' which in this example are the same.