问题

I'm trying to check if a function returns true in an if/else statement, however I want to keep checking if the function returns true and when it does to execute the code...

我试图在if/else语句中检查函数是否返回true，但我想要持续检查函数是否返回true，当它返回true时执行代码...

How would I go about this? I have tried setInterval and setTimeout and it won't repeat, unless I'm missing something...

我应该如何做到这一点？我尝试过setInterval和setTimeout，但它不会重复，除非我漏掉了什么...

I have also tried a while loop but this is inefficient and crashes the browser...

我还尝试过使用while循环，但这是低效的，并且会导致浏览器崩溃...

However if I use an setInterval() how would I clear it once x returns true?

但如果我使用setInterval()，一旦x返回true，我该如何清除它？

Here is a snippet of my code for an example.

以下是我的示例代码片段。

function x() {
    if (localStorage.getItem("a") === null) {
        return false;
    } else {
        return true;
    }
}
if (!x()) {
    console.log("Returned True!");
    update();
} else {
    console.log("False");
}

function x() {
    if (localStorage.getItem("a") === null) {
        return false;
    } else {
        return true;
    }
}
if (!x()) {
    console.log("Returned True!");
    update();
} else {
    console.log("False");
}

答案1

得分: 1

setInterval() 应该可以工作。

function x() {
    return localStorage.getItem("a") !== null;
}
let interval = setInterval(() => {
    if (x()) {
        console.log("Returned True!");
        update();
        clearInterval(interval);
    } else {
        console.log("False");
    }
}, 500);

function x() {
    return localStorage.getItem("a") !== null;
}
let interval = setInterval(() => {
    if (x()) {
        console.log("Returned True!");
        update();
        clearInterval(interval);
    } else {
        console.log("False");
    }
}, 500);

答案2

得分: 0

function x() {
if (localStorage.getItem("a") === null) {
return false;
} else {
return true;
}
}

setInterval(x(), 1000);
setInterval(x, 1000);

第一个将在第二个清除之前运行一次。

function x() {
    if (localStorage.getItem("a") === null) {
        return false;
    } else {
        return true;
    }
}
setInterval(x(), 1000);
setInterval(x, 1000);