JavaScript如何处理未知的价值? [英] How does JavaScript deals with value which is unknown?

问题描述

我是JavaScript的新手，正在阅读书，在递归章节中，有一个示例跟随

I am new to JavaScript and reading a book and in recursive chapter, there is an example as follow

function findSolution(target) {
  function find(current, history) {
    if (current == target)
      return history;
    else if (current > target)
      return null;
    else
      return find(current + 5, "(" + history + " + 5)") ||
             find(current * 3, "(" + history + " * 3)");
  }
 *return find(1, "1"); // when will this run?
}

console.log(findSolution(24));
// → (((1 * 3) + 5) * 3)

我无法理解JavaScript将如何运行这些原因，因为在所有三种 if 情况下，它期望 current 的值?但是作者只是运行函数的外部，该函数以 target 作为参数，而不是 current 作为参数.它是否采用

I am unable to understand how does JavaScript will run these causes as it expects a value of current in all three if cases? But the author is just running the outside of function which takes target as an argument, not the current. Does it take value of current and history from

return find(1,"1")

喜欢吊装吗?

推荐答案

current 和 history 是为 fund 上的参数指定的名称函数，而不是 findSolution 函数.

current and history are the names given to parameters on the fund function, not the findSolution function.

所以是的，当使用 find(1，"1")调用该函数时，它将获得这些值(然后，当 find(current * 5，…)时，它将获得这些值. 和 find(current + 3, ...) 被调用.

So yes, it will get those values when find(1, "1") is used to call that function (and then later, when find(current * 5, …) and find(current + 3, …) are called).

这在任何方面都不像起重或与起重有关.

This is not, in any way, like or related to hoisting.

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