我不能让setInterval（）在Javascript中工作 [英] I can't get setInterval() to work in Javascript

问题描述

我有一个生成给定单词排列的算法。我正在尝试使用 setInterval（）来生成下一个排列，但该函数只运行一次！我无法弄清楚为什么。我没有收到任何错误消息。
这是我的代码

i have an algorithm that generates permutations of a given word. I'm trying to use setInterval() to generate the next permutation but the function runs only once! I can't figure out why. I don't get any error messages. Here is my code

var splitted;
var t;
 $(document).ready(function() {
$('#SubmitBtn').click(function() {
    //change Start to Stop and change button id
    $('#SubmitBtn').attr('id','StopBtn').attr('value','Stop');
    //and add click event to it
    $('#StopBtn').click(function() {
        clearInterval(t);
        $('#StopBtn').attr('value','Submit');
        $('StopBtn').attr('id','SubmitBtn');
    });
    if ($('#AnagramTxtArea').val().length>0)
            $('#AnagramTxtArea').text('');
    var inputTxt = $('#anagram').val();
    splitted = inputTxt.split("");
    splitted.sort(); //first sort the array in order to generate permutations
    $('#AnagramTxtArea').append(splitted.join("") + " ");
    t= setInterval(GeneratePermutation(),10);
});
 });

 var AnagramObj = new Anagram();
 function GeneratePermutation() {
        splitted = AnagramObj.NextPermutation(splitted);
        if (splitted!=null)
            $('#AnagramTxtArea').append(splitted.join("") + " ");       
        else  
            $('#StopBtn').click();

    }

和HTML：

<div id="content">
<input id="anagram" type="text" placeholder="Insert your text here" maxlength="80"/>                    <br />
<input id="SubmitBtn" type="submit" value="submit" />
<br />
<textarea id="AnagramTxtArea" readonly="readonly"></textarea>

</div> 

编辑：
然而，另一个问题是：

Yet, another problem:

调用$（'＃StopBtn'）时，click（）代码在现有click事件函数后继续执行。所以我处在一个无限循环中。

When calling $('#StopBtn').click() code continues to execute after existing the click event function. So i'm in an infinite loop.

推荐答案

您需要将函数对象本身传递给 setInterval（） ，而不是调用函数的结果：

You need to pass the function object itself to setInterval(), not the result of a call to the function:

t = setInterval(GeneratePermutation,10);
                                // ^ No parentheses

编辑：在你的第二个问题，你能做的是检查间隔是否正在运行。如果是，则取消它：

On your second question, what you can do is check whether the interval is running. If it is, then cancel it:

var splitted;
var t;
$(document).ready(function() {
$('#SubmitBtn').click(function() {
    if (t !== undefined) { //interval is already running
        clearInterval(t);
        t = undefined;
        $('#SubmitBtn').attr('value','Submit');
    } else {
        //change Start to Stop
        $('#SubmitBtn').attr('value','Stop');
        if ($('#AnagramTxtArea').val().length>0)
                $('#AnagramTxtArea').text('');
        var inputTxt = $('#anagram').val();
        splitted = inputTxt.split("");
        splitted.sort(); //first sort the array in order to generate permutations
        $('#AnagramTxtArea').append(splitted.join("") + " ");
        t = setInterval(GeneratePermutation,10);
    }
});
});

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