javascript - 如何删除/删除 JavaScript function()？

Question

如果检测到某个浏览器，我该如何删除某个功能？ 这是功能和检测:

function parallaxIt(e, target, movement) {
  var $this = $("#app");
  var relX = e.pageX - $this.offset().left;
  var relY = e.pageY - $this.offset().top;

  TweenMax.to(target, 1, {
    x: (relX - $this.width() / 2) / $this.width() * movement,
    y: (relY - $this.height() / 2) / $this.height() * movement,
    z: 0.01,
    rotation:0.01
  });
}


var version = detectIE();
if (version === false) {
  //Do Nothing
} else if (version >= 12) {
    //Remove Function
} else {
    $("#iefix").attr({href : "/static/css/app-iefix.css"});
    //Remove Function
}

因此，当检测到任何 IE 时，我想删除函数 parallaxIt() 或破坏它，这样它就不起作用了？ 亲切的问候

(代码的检测部分显然是完整代码的一小段，因此您更容易阅读而不是阅读完整代码)

Answer 1

至少对我来说，在 Chrome v71 (Windows 10) 中，删除该功能没有任何作用(它保持存在)。但是您可以重新分配它成为一个空操作函数:

function parallaxIT() {
  console.log("inside parallaxIT");
}

// delete
delete window.parallaxIT;
console.log("parallaxIT was 'deleted', does it still show output:");
parallaxIT();

console.log("=====");

// re-assign
window.parallaxIT = function() {}    // no-op function
console.log("parallaxIT was re-assigned, does it still show output:");
parallaxIT();

console.log("=====");