JavaScript 中的可选参数 [英] Optional arguments in JavaScript

问题描述

如果缺少剩余参数，为什么这个函数不会抛出错误?

Why doesn't this function throw an error if the remaining arguments are missing?

showStatistics("Mark Teixeira", "New York Yankees", "1st Base");

这是定义的函数:

function showStatistics(name, team, position, average, homeruns, rbi) {
  document.write("<p><strong>Name:</strong> " + arguments[0] + "<br />");
  document.write("<strong>Team:</strong> " + arguments[1] + "<br />");

  if (typeof arguments[2] === "string") {
    document.write("<strong>Position:</strong> " + position + "<br />"); 
  }
  if (typeof arguments[3] === "number") {
    document.write("<strong>Batting Average:</strong> " + average + "<br />");
  }
  if (typeof arguments[4] === "number") {
    document.write("<strong>Home Runs:</strong> " + homeruns + "<br />");
  }
  if (typeof arguments[5] === "number") {
    document.write("<strong>Runs Batted In:</strong> " + rbi + "</p>"); 
  }
}

推荐答案

任何未传递的参数在函数内都显示为 undefined.在 JavaScript 中没有方法重载.

Any argument that is not passed appears as undefined inside the function. In JavaScript there is no method overloading.

这篇关于JavaScript 中的可选参数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！