javascript - 在 HTML 文档中显示循环函数的正确语法

Question

我有点不明白为什么这段代码没有显示任何内容，它曾经在我没有按钮的包装函数并且我在脚本中手动输入分解函数的参数时工作，什么我做错了吗？

HTML

<div class="factorializing">

  <h1> Factorialize a number </h1>

    <input type ="text" id ="number"/>
    <button id="factButton"> Factorialize</button>

  <h1 id="factorialized"> </h1>

</div>

Javascript

document.getElementById("factButton").addEventListener("click", function(){

 function factorialize() {
   var input = document.getElementById("number").value;
   var output = document.getElementById("factorialized");

if (input === 0) {
   return output.innerHTML =  1;
}

else {
   return output.innerHTML = input * factorialize(input - 1) ;
}            
}
 });

Answer 1

我认为您正在寻找这样的东西:-

document.getElementById("factButton").addEventListener("click", function() {

  var input = document.getElementById("number").value;
   var output = document.getElementById("factorialized");
  
  function factorialize(input) {
    if (input === 0) {
      return 1;
    } else {
      return input * factorialize(input - 1);
    }
  }
  
  output.innerHTML = factorialize(input);
});

<div class="factorializing">

  <h1> Factorialize a number </h1>

  <input type="text" id="number" />
  <button id="factButton">Factorialize</button>

  <h1 id="factorialized"> </h1>

</div>

这将递归调用您的factorialize函数并设置输出。