如何防止变量在某一点之后被使用？

Question

function exampleFunction(){
    var theVariable = "Lol!";
    var variable2 = Lol.toLowerCase();
    console.log(theVariable);
    delete theVariable; //to prevent bugs, I want to ensure that this variable is never used from this point onward.
    console.log(theVariable); //This still prints "Lol!", even though I just tried to delete the variable.
}

在JavaScript中,是否可以防止变量在某个点之后在函数中使用？我已经尝试声明一个名为的字符串theVariable,然后我尝试使用删除变量delete theVariable,但即使在那之后console.log(theVariable)仍然打印出来theVariable的值.

我试着使用delete theVariable,使theVariable从该点以后不可用(为了防止自己不小心使用时不再需要它的变量),但它不会出现有这种效果.有没有办法解决这个限制？

Answer 1

一种方法是限制其范围.由于JavaScript没有块范围,因此需要IIFE(或类似技术):

function exampleFunction(){
    var variable2;
    (function() {
        var theVariable = "Lol!";
        variable2 = Lol.toLowerCase();
        console.log(theVariable);
    })();
    // theVariable is now out of scope, and cannot be referenced
}