运行以下代码时遇到奇怪的结果：
var saySomethingElse, v;
// This function will not run when the nameless function runs, even if v and saySomethingElse are commented out.
function saySomething() {
alert("something");
}
// When v is uncommented, this function will run when the nameless function below runs..
saySomethingElse = function() {
alert("something else");
}
//v = "by uncommenting me, saySomethingElse will no longer be called.";
(function() {
if (v) {
alert("Now things are working normally.")
}
alert("This alert doesn't happen if v is commented out.");
})();
当此代码运行时，底部的匿名函数调用saySomethingElse而不是其自己的内容，但如果取消注释v，则一切都按预期工作：saySomethingElse未执行，并且匿名函数执行自己的内容。我希望这可能是正常行为，但我正在寻找解释。有谁知道为什么会这样？
查看小提琴：working example
答案 0 :(得分：1)
您需要在匿名函数saySomethingElse
您应始终使用分号正确结束匿名函数。
。不需要使用分号来结束正常的非匿名function fooBar() {}函数。
var saySomethingElse, v;
// This function will not run when the nameless function runs, even if v and saySomethingElse are commented out.
function saySomething() {
alert("something");
} // <-- Semi-colon not necessary.
// When v is uncommented, this function will run when the nameless function below runs..
saySomethingElse = function() {
alert("something else");
}; // <-- Semi-colon recommended to prevent errors like you're getting.
//v = "by uncommenting me, saySomethingElse will no longer be called.";
(function() {
if (v) {
alert("Now things are working normally.")
}
alert("This alert doesn't happen if v is commented out.");
})();
现在代码的功能正如您所期望的那样saySomethingElse已在最后正确终止。
这是因为，在JavaScript中，您应该在每个语句的末尾使用分号。匿名函数定义是语句，就像任何其他变量定义一样。