javascript - while 循环不执行或不循环？

Question

// require '04_wonky_coins'
// require 'rspec'
//
// # Catsylvanian money is a strange thing: they have a coin for every
// # denomination (including zero!). A wonky change machine in
// # Catsylvania takes any coin of value N and returns 3 new coins,
// # valued at N/2, N/3 and N/4 (rounding down).
// #
// # Write a method `wonky_coins(n)` that returns the number of coins you
// # are left with if you take all non-zero coins and keep feeding them
// # back into the machine until you are left with only zero-value coins.
// #
// # Difficulty: 3/5
//
// describe "#wonky_coins" do
//   it "handles a coin of value 1" do
//     wonky_coins(1).should == 3
//   end
//
//   it "handles a coin of value 5" do
//     wonky_coins(5).should == 11
//     # 11
//     # => [2, 1, 1]
//     # => [[1, 0, 0], [0, 0, 0], [0, 0, 0]]
//     # => [[[0, 0, 0], 0, 0], [0, 0, 0], [0, 0, 0]]
//   end
//
//   it "handles a coin of value 6" do
//     wonky_coins(6).should == 15
//   end
//
//   it "handles being given the zero coin" do
//     wonky_coins(0).should == 1
//   end
// end
function check_coins(hand){
  for(var i=0; i<hand.length; i++){
    var coin = hand[i]
     if(coin !==0){
      return i;
    } else {
      return null;
    }
  }
  return false;
}


function wonkyCoins(n){
  var hand = [];

  hand.push(Math.floor(n/2));
  hand.push(Math.floor(n/3));
  hand.push(Math.floor(n/4));




 while(check_coins(hand){

  var indx = check_coins(hand);


  var value = hand[indx];

  var index1 = hand.indexOf(hand[indx]);

  if (index1 > -1) {
     hand.splice(index1, 1);
  }


  hand.push(Math.floor(value/2));
  hand.push(Math.floor(value/3));
  hand.push(Math.floor(value/4));

 }

return hand.length;

}

程序运行正常，但 while 循环由于某些原因没有循环。我怀疑条件有问题。我不确定 javaScript 是否接受这种条件。但是，在 ruby​​ 中它起作用了。有人可以为我解释为什么不起作用吗？

Answer 1

您错过了一个圆括号来关闭您的 while 循环条件参数。您的代码实际上应该是:

while(check_coins(hand)){

  ... 

 }

如果这不起作用，则可能是条件本身。尝试:

while(check_coins(hand) !== null){

... 

}