如何知道递归函数何时停止调用自身？

Question

有什么方法可以知道递归函数何时停止调用自身？

我有以下场景：

function print(msg){
  console.log(msg);
  
  if(canContinue){
    print("Hi there");
  }

  if(canContinueCase2){
    setTimeout(()=>{
      print("I was late to the party");
    }, 2000);
  }

  if(canContinueCase3){
    print("Cool right?");
  }

  if(canContinueCase4){
    if(canContinueCase5 && !otherBoolean){
      print("Thank you!");
    }
  }
}

canContinue, canContinueCase2, ... otherBoolean 是全局变量（布尔值）。如何知道函数 print(msg) 何时不再被调用？换句话说，我怎么知道算法已经停止？

Answer 1

您可以在开始时一起测试布尔值。如果其中任何一个 === true 它不是 finished

function print(msg){
  let finished = !(canContinue || canContinueCase2 || canContinueCase3 || canContinueCase4 || canContinueCase5 || otherBoolean);
  // ...
}

Answer 2

您可以使用计数器：

let counter = 0;

function print(msg){
  console.log(msg);
  
  if(canContinue){
    counter++;
    print("Hi there");
  }

  if(canContinueCase2){
    counter++;
    setTimeout(()=>{
      print("I was late to the party");
    }, 2000);
  }

  if(canContinueCase3){
    counter++;
    print("Cool right?");
  }

  if(canContinueCase4){
    if(canContinueCase5 && !otherBoolean){
      counter++;
      print("Thank you!");
    }
  }
  counter--;
}

counter++;
print("hi");

//to check if the function is done, use this:
if (counter == 0) {
  
}

如何知道递归函数何时停止调用自身？

How to know when a recursive function has stopped calling itself?

javascript

algorithm

recursion

settimeout