if语句不在for循环中执行

Not sure why the if statement inside the second for loop not executing, anyone who can point me in the right direction would be appreciated.

不知道为什么第二个for循环中的if语句没有执行,任何能指出我正确方向的人都会受到赞赏。

function checkCashRegister(price, cash, cid) {
  var change;
  var balance = [];
  var total = 0;
  for (var i = 0; i<cid.length; i++) {
    total += cid[i][1];
    change = cash - price;  
    if (total < change) {
      return "Insufficient Funds";
    } else if (total === change) {
      return "Closed";
    } 
  }
  for (var x = 8; x >= 0; x--) {
    if (change > cid[x][1] && change <= cid[x][1]) {
      balance.push(cid[x-1][1]);
    }
  }
  return balance;
} //end function

checkCashRegister(19.50, 20.00, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME",     3.10], ["QUARTER", 4.25], ["ONE", 90.00], ["FIVE", 55.00], ["TEN", 20.00], ["TWENTY", 60.00], ["ONE HUNDRED", 100.00]]);

2 个解决方案

#1

The if statement is trying to check if change is greater than cid[x][1] AND if change is less than/equal to cid[x][1].

if语句试图检查更改是否大于cid [x] [1]并且如果更改小于/等于cid [x] [1]。

This will never be true.

这永远不会成真。

change will always either be greater than cid[x][1] or less than/equal to it.

更改将始终大于cid [x] [1]或小于/等于它。

#2

Let's look at the logic of the if statement: change > cid[x][1] && change <= cid[x][1]

让我们看一下if语句的逻辑:change> cid [x] [1] && change <= cid [x] [1]

You're saying that if change is greater than cid[x][1] AND change is less than or equal to cid[x][1]. That logic will never execute because one number can never be both larger AND smaller than or equal to another's number at the same time.

你说如果变化大于cid [x] [1]并且变化小于或等于cid [x] [1]。该逻辑永远不会执行,因为一个数字永远不能同时大于或小于或等于另一个数字。

Let change = 5 and cid[x][1] = 0.25, plugging those value into the logic you'll see that it's not possible for 5 to be larger AND smaller than or equal to 0.25 at the same time. (5 > 0.25 && 5 <= 0.25).

让change = 5和cid [x] [1] = 0.25,将这些值插入到逻辑中,您将看到5不可能同时大于和小于或等于0.25。 (5> 0.25 && 5 <= 0.25)。

#1