JavaScript Algorithms and Data Structures Projects - Cash Register

JavaScript
1

Tell us what’s happening:
Hi everyone,
this is my code for the JS challenge " Cash Register".
I can pass other tests except for this one:
checkCashRegister(3.26, 100, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]]) should return {status: "OPEN", change: [["TWENTY", 60], ["TEN", 20], ["FIVE", 15], ["ONE", 1], ["QUARTER", 0.5], ["DIME", 0.2], ["PENNY", 0.04]]} .

Can somebody helps me debug ? Thanks a lot.

Your code so far

function checkCashRegister(price, cash, cid) {
  let change=cash-price;
  let sum=0;
  for (let i=0;i<cid.length;i++){
    sum+=cid[i][1];
  }
  if(change === sum){
    return {status: "CLOSED", change: cid}
  } else if (change > sum){
    return {status: "INSUFFICIENT_FUNDS", change: []}
  } else {
    let output=[];
    let table=[100,20,10,5,1,0.25,0.1,0.05,0.01];
    let newCid=cid.reverse();
    for (let i=0;i<newCid.length;i++){
      if (change<=newCid[i][1]){
        output.push(parseInt(change/table[i])*table[i]);
        change -= parseInt(change/table[i])*table[i];
      } else {
        output.push(newCid[i][1]);
        change -= newCid[i][1];
      }  
      
    }
    if (change===0){
      let result=[];
      let map=[
  ["ONE HUNDRED", output[0]],
  ["TWENTY", output[1]],
  ["TEN", output[2]],
  ["FIVE", output[3]],
  ["ONE", output[4]],
  ["QUARTER", output[5]],
  ["DIME", output[6]],
  ["NICKEL", output[7]],
  ["PENNY", output[8]]
];
for (let i=0;i<map.length;i++){
  if (map[i][1]!==0){
result.push(map[i]);
  }
}
return {status: "OPEN", change: result }
    }else {return {status: "INSUFFICIENT_FUNDS", change: []}
    }  
  }
  
}


checkCashRegister(19.5, 20, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]]);

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36

Challenge: JavaScript Algorithms and Data Structures Projects - Cash Register

Link to the challenge:

2

First question: Do you know what that test is actually returning when run against your code?

3

{
“status”: “INSUFFICIENT_FUNDS”,
“change”:
}

4

Perfect. So that tells you that this if statement:

if (change === 0) {

isn’t working as intended, because you know the answer should return status: "OPEN".

Do you have any insight into why change doesn’t equal 0 there for this particular test? What do you think you could do to troubleshoot this?

5

Hi, thanks a lot. I tried to print the test result and it comes out : {
“status”: “OPEN”,
“change”: [
[
“TWENTY”,
60
],
[
“TEN”,
20
],
[
“FIVE”,
15
],
[
“ONE”,
1
],
[
“QUARTER”,
0.5
],
[
“DIME”,
0.2
],
[
“PENNY”,
0.03
]
]
}
So the problem is that the result of “Penny” becomes 0.03 while it supposed to be 0.04.

6

Sorry, I don’t think I’m following you. Using the code you originally pasted above, for the test case that is not passing your function is returning

{ status: 'INSUFFICIENT_FUNDS', change: [] }

So I’m not sure where you got that “PENNY” is 0.03? Have you changed your code? If so, please paste in the newer version.

7 
function checkCashRegister(price, cash, cid) {
  let change=cash-price;
  let sum=0;
  for (let i=0;i<cid.length;i++){
    sum+=cid[i][1];
  }
  if(change === sum){
    return {status: "CLOSED", change: cid}
  } else if (change > sum){
    return {status: "INSUFFICIENT_FUNDS", change: []}
  } else {
    let output=[];
    let table=[100,20,10,5,1,0.25,0.1,0.05,0.01];
    let newCid=cid.reverse();
    for (let i=0;i<newCid.length;i++){
      if (change<=newCid[i][1]){
        output.push(parseInt(change/table[i])*table[i]);
        change -= parseInt(change/table[i])*table[i];
      } else {
        output.push(newCid[i][1]);
        change -= newCid[i][1];
      }  
      
    }
    
      let result=[];
      let map=[
  ["ONE HUNDRED", output[0]],
  ["TWENTY", output[1]],
  ["TEN", output[2]],
  ["FIVE", output[3]],
  ["ONE", output[4]],
  ["QUARTER", output[5]],
  ["DIME", output[6]],
  ["NICKEL", output[7]],
  ["PENNY", output[8]]
];
for (let i=0;i<map.length;i++){
  if (map[i][1]!==0){
result.push(map[i]);
  }
}
return {status: "OPEN", change: result }
    
  }
  
}

Sorry, I forgot to telle you that I did change a little bit of the last part of my code, just to see the result , in order to know why if (change === 0) {

isn’t working as intended.

8

What might you want to look at in order to figure this out? Since you making decisions based on the value of change, maybe it would be a good idea to see what the value of change is for this particular test? Perhaps see how the value of change changes as you are trying to figure out if you can make change.

9

I’ve edited your code for readability. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.

You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.

Pre-formatted-text
Pre-formatted-text1356×380 401 KB

See this post to find the backtick on your keyboard.
Note: Backticks (`) are not single quotes (').

10

HI, thanks a lot, I added a line of code :
change = Math.round(change * 100) / 100;
after :
change -= parseInt(change/table[i])*table[i];
and the problem is solved.

11

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