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JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Useful Array Methods

Posted by Christopher Jauregui
Christopher Jauregui
1,967 Points

Why won't my grocery list display when i type "list" i have to type exit for prompt to quit then view.

06:54 into the video he runs the code and the list will display behind prompt then he types quit to exit prompt. When i run the same code I it will not show until i type quit the grocery list shows , but if i add a "break" at the end of the else if statement it works? var inStock = [ 'apples', 'eggs', 'milk', 'cookies', 'cheese', 'bread', 'lettuce', 'carrot', 'broccoli', 'pizza', 'potato', 'crackers', 'onion', 'tofu', 'frozen dinner', 'cucumber']; var search;

function print(message) { document.write( '<p>' + message + '</p>'); }

while (true) { search = prompt("Search the product in the store. Type 'list' to show al of the products in the stock and 'break' to exit" ); if (search === 'quit'){ break;

}else if (search === 'list'){ print(inStock.join(', ')); break; } }

4 Answers

andren
andren
28,558 Points
andren
andren
28,558 Points

This is explained in the teacher's notes of the video:

Since this video was shot, the behavior of most browsers has changed, so you won't see the same thing as I demonstrate in the video. In the video, you'll see that my script is able to print out to the browser using document.write( ) while inside a loop.

Most browsers no longer do that: they wait until the loop finishes and then they print to the window. So, you'll see a blank page until you type quit in the prompt window — then you'll see all the output printed to the screen.

Sorry for the confusion, and we'll update the video soon.

Christopher Jauregui
Christopher Jauregui
1,967 Points

Wow first time i have gotten a response from the actual person in the video. This is the first question i have had for you guys good to know you guys have a responsive team . Thanks for the help.

danielperez
seal-mask
.a{fill-rule:evenodd;}techdegree
danielperez
Full Stack JavaScript Techdegree Student 15,993 Points
danielperez
.a{fill-rule:evenodd;}techdegree
danielperez
Full Stack JavaScript Techdegree Student 15,993 Points 
// one solution : remove while loop, use the if-else statement by itself
// main change : if statement tests for  'list' first, then print list
// then inner if-else tests for inStock.indexof matching or not, 
// final else simply prints 'thanks for shopping' 

// tested this code on macOS 10.13.2 and latest versions Safari and Chrome

// array of items in stock

var inStock = [ 'apples', 'eggs', 'milk', 'cookies', 'cheese', 'bread', 'lettuce', 'carrot', 'broccoli', 'pizza', 'potato', 'crackers', 'onion', 'tofu', 'frozen dinner', 'cucumber'];

// empty search variable, to store, indexOf. Use this to test against inStock list 

var search;

// added, thankForShopping, string variable 
// used it to give the final else 'quit' something to do
// and then print this after each either list or search result also

var thanksForShopping = 'Thanks for Shopping. Please come, again';

function print(message) {
  document.write( '<p><strong>' + message + '</strong></p>');
}

search = prompt("Search for a product in our store. Type 'list' to show all of the produce and 'quit' to exit");
search = search.toLowerCase();

if ( search === 'list' ) {
    print( inStock.join(',  ') );
  } else if (search !== 'quit') {
    if ( inStock.indexOf( search ) > -1 ) {
      print( 'Yes, we have ' + search + ' in the store.');
      print(thanksForShopping);

    } else {
      print( search + ' is not in stock.');
      print(thanksForShopping);

    }
  } else {
    print(thanksForShopping);
  }

// commmented out the while-loop
/* while (true) {
  search = prompt("Search for a product in our store. Type 'list' to show all of the produce and 'quit' to exit");
  search = search.toLowerCase();
  if ( search === 'quit') {
    break;
  } else if ( search === 'list' ) {
    print( inStock.join(', ') ); 
  } else {
    if ( inStock.indexOf( search ) > -1 ) {
      print( 'Yes, we have ' + search + ' in the store.');
    } else {
      print( search + ' is not in stock.'); 
    }
  }
}
*/
Andrea Dinh
Andrea Dinh
4,946 Points
Andrea Dinh
Andrea Dinh
4,946 Points

Hi, this might be a late contribution, but I had the same problem, and then I figured I could just put "break" after "print" like this: else if ( request === "list" ) { print( inStock.join(", ") ); break; }

Hope this helps

Jeffrey Libatique
Jeffrey Libatique
6,701 Points
Jeffrey Libatique
Jeffrey Libatique
6,701 Points

Hi Andrea,

I did your suggestion and it worked.

Thanx a lot!

Saqib Ishfaq
Saqib Ishfaq
13,912 Points
Saqib Ishfaq
Saqib Ishfaq
13,912 Points

Thanks andrea, just came across ur answer here, yes it helped by adding " break; " after "print". do u mean just on one occasion? coz as per teacher's notes, for browsers its not been working according to the code, adding "break; " after every "print" works just fine.

Jarom Denny
Jarom Denny
4,081 Points
Jarom Denny
Jarom Denny
4,081 Points

If you write break after each print function you can only call one test at a time. The other option is to add an alert to the print function so you get real time responses. i.e. function print(message) { document.write( '<p>' + message + '</p>'); alert(message); }

alee2
alee2
5,435 Points
alee2
alee2
5,435 Points

Thanks Andrea Dinh this works!

hope the video get updated soon.