Codehs Inventory: What am I doing wrong in this code?

I am working on this code long time and still can't figure out what is wrong here... when I click on check code it says that:

1. If I tried to remove 25 items, there should still be 20 items left in the inventory
2. If I remove 20 items, you should say "All Out!"

but my code is working in both situations. So here is my code:

var STARTING_ITEMS_IN_INVENTORY = 20; function start(){ var numItems = STARTING_ITEMS_IN_INVENTORY; while(numItems>0 ){ println("We have "+numItems+" items in inventory"); var number=readInt("How many would you like to buy?"); numItems-=number; if(numItems>0){ println("Now we have "+numItems+" left"); println(""); } if(numItems==0){ println(""); println("All Out!"); }else if(numItems<0){ println("There is not enough in inventory for that purchase"); } } } 

Please help me with this problem

2 Answers

You tagged your post javascript but your code is not. I bet it's your homework for tomorrow...

I rewrote your code to fit js needs :

var STARTING_ITEMS_IN_INVENTORY = 20; function start() { var numItems = STARTING_ITEMS_IN_INVENTORY; while (numItems > 0) { alert("We have " + numItems + " items in inventory"); var number = prompt("How many would you like to buy?"); numItems -= number; if (numItems > 0) { alert("Now we have " + numItems + " left"); } else if (numItems == 0) { alert("All Out!"); } else if (numItems < 0) { alert("There is not enough in inventory for that purchase"); } } } start();

I give you the following code, that's what you want, I advise you to modify it to understand how algorithmic and js work.

var STARTING_ITEMS_IN_INVENTORY = 20; function start() { var numItems = STARTING_ITEMS_IN_INVENTORY; while (numItems > 0) { var number = prompt("How many would you like to buy? (" + numItems + " left)"); if (numItems - number > 0) { numItems -= number; } else if (numItems - number == 0) { numItems -= number; } else if (numItems - number < 0) { alert("There is not enough in inventory for that purchase, please retry"); } } alert("All Out!"); } start();

advises and infos :

• readLn() and printLn() are not core functions in javascript
• in web dev you should not use prompt() nor alert() for that purpose
• check the future item count of the inventory before asign it to the numItems
• read

I found this to be the simplest way to satisfy the autochecker.

var STARTING_ITEMS_IN_INVENTORY = 20; function start() { var numItems = STARTING_ITEMS_IN_INVENTORY; while(numItems > 0){ println("We have " + numItems + " items in inventory."); var howMany = readInt("How many items would you like to buy? "); if(howMany > numItems){ println("There is not enough in inventory for that purchase."); println(""); } else { numItems -= howMany; println("Now we have " + numItems + " left."); println(""); } } println("All Out!"); }