在`setInterval`内部计算数组中的元素数量：Javascript

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英文:

Count no. of elements in an array inside setInterval : Javascript

问题

我有一个包含元素的数组。

我想要的是，在JavaScript中，每次Set Interval函数加载时都计算元素的数量。

类似于计数器，但当我使用count函数时，它显示一个错误：

Uncaught TypeError: x.count is not a function

我只想要在setinterval函数发生时每次从0开始计算值的数量。

以下是代码：

  1. var countArray = ["2020-14-03 11:14:48.225000","2020-14-03 11:14:48.226000","2020-14-03 11:14:48.227000","2020-14-03 11:14:48.228000","2020-14-03 11:14:48.229000","2020-14-03 11:14:48.230000","2020-14-03 11:14:48.231000","2020-14-03 11:14:48.232000","2020-14-03 11:14:48.233000","2020-14-03 11:14:48.234000","2020-14-03 11:14:48.235000","2020-14-03 11:14:48.236000","2020-14-03 11:14:48.237000","2020-14-03 11:14:48.238000","2020-14-03 11:14:48.239000","2020-14-03 11:14:48.240000","2020-14-03 11:14:48.241000","2020-14-03 11:14:48.242000","2020-14-03 11:14:48.243000","2020-14-03 11:14:48.244000"];
  3. console.log(countArray.length);
  5. var j = 0;
  7. function countval() {
  8.   return countArray[j++];
  9. }
  11. setInterval(function() {
  12.   var counter = j - 1;
  13.   console.log("Count: ", counter);
  14. }, 1000);

例如：console.log("Count: ", counter); 应该在每秒后打印：

0
1
2
3
4
5
6
7
8
9

更新：
我的问题是字符串格式的。我想要计算数组中字符串元素的出现次数。

英文:

I have an array containing elements .

What I want is to count the no. of elements every time when the Set Interval function loads in javascript.

Something like a counter but when I am using the count function it's displaying an error :

> Uncaught TypeError: x.count is not a function

I just want to count the no. of values when setinterval function occurs every time starting from 0 .

Here is the Code :

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

  1. var countArray = [&quot;2020-14-03 11:14:48.225000&quot;,&quot;2020-14-03 11:14:48.226000&quot;,&quot;2020-14-03 11:14:48.227000&quot;,&quot;2020-14-03 11:14:48.228000&quot;,&quot;2020-14-03 11:14:48.229000&quot;,&quot;2020-14-03 11:14:48.230000&quot;,&quot;2020-14-03 11:14:48.231000&quot;,&quot;2020-14-03 11:14:48.232000&quot;,&quot;2020-14-03 11:14:48.233000&quot;,&quot;2020-14-03 11:14:48.234000&quot;,&quot;2020-14-03 11:14:48.235000&quot;,&quot;2020-14-03 11:14:48.236000&quot;,&quot;2020-14-03 11:14:48.237000&quot;,&quot;2020-14-03 11:14:48.238000&quot;,&quot;2020-14-03 11:14:48.239000&quot;,&quot;2020-14-03 11:14:48.240000&quot;,&quot;2020-14-03 11:14:48.241000&quot;,&quot;2020-14-03 11:14:48.242000&quot;,&quot;2020-14-03 11:14:48.243000&quot;,&quot;2020-14-03 11:14:48.244000&quot;];
  3. console.log(countArray.length);
  6. var j = 0;
  8. function countval() {
  9.   return countArray[j++];
  10. }
  12. setInterval(function() {
  13.   var counter = 0;
  14.   x = countval();
  15.   console.log(&quot;X value: &quot;, x);
  16.   counter = x.count();
  17.   console.log(&quot;Count: &quot;, counter);
  18. }, 1000);

<!-- end snippet -->

for example: console.log(&quot;Count: &quot;, counter); should print:

  1. 0
  2. 1
  3. 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. 7
  9. 8
  10. 9

after each second.

Update:
My queston is of string format. how so I want to count the no. of string elements occurence in an array.

答案1

得分: 1

你的问题已经通过这段代码解决了：

  1. var countArray = ["2020-14-03 11:14:48.225000","2020-14-03 11:14:48.226000","2020-14-03 11:14:48.227000","2020-14-03 11:14:48.228000","2020-14-03 11:14:48.229000","2020-14-03 11:14:48.230000","2020-14-03 11:14:48.231000","2020-14-03 11:14:48.232000","2020-14-03 11:14:48.233000","2020-14-03 11:14:48.234000","2020-14-03 11:14:48.235000","2020-14-03 11:14:48.236000","2020-14-03 11:14:48.237000","2020-14-03 11:14:48.238000","2020-14-03 11:14:48.239000","2020-14-03 11:14:48.240000","2020-14-03 11:14:48.241000","2020-14-03 11:14:48.242000","2020-14-03 11:14:48.243000","2020-14-03 11:14:48.244000"];
  3. console.log(countArray.length);
  5. var j = 0;
  7. function countval() {
  8.   return countArray[j++];
  9. }
  11. setInterval(function() {
  12.   if(j <= countArray.length){
  13.     var counter = 0;
  14.     console.log("Count: ", j);
  15.     console.log("X value: ", countval());
  16.   }
  17. }, 1000);
英文:

Your problem is solved with this code

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

  1. var countArray = [&quot;2020-14-03 11:14:48.225000&quot;,&quot;2020-14-03 11:14:48.226000&quot;,&quot;2020-14-03 11:14:48.227000&quot;,&quot;2020-14-03 11:14:48.228000&quot;,&quot;2020-14-03 11:14:48.229000&quot;,&quot;2020-14-03 11:14:48.230000&quot;,&quot;2020-14-03 11:14:48.231000&quot;,&quot;2020-14-03 11:14:48.232000&quot;,&quot;2020-14-03 11:14:48.233000&quot;,&quot;2020-14-03 11:14:48.234000&quot;,&quot;2020-14-03 11:14:48.235000&quot;,&quot;2020-14-03 11:14:48.236000&quot;,&quot;2020-14-03 11:14:48.237000&quot;,&quot;2020-14-03 11:14:48.238000&quot;,&quot;2020-14-03 11:14:48.239000&quot;,&quot;2020-14-03 11:14:48.240000&quot;,&quot;2020-14-03 11:14:48.241000&quot;,&quot;2020-14-03 11:14:48.242000&quot;,&quot;2020-14-03 11:14:48.243000&quot;,&quot;2020-14-03 11:14:48.244000&quot;];
  3. console.log(countArray.length);
  6. var j = 0;
  8. function countval() {
  9.   return countArray[j++];
  10. }
  12. setInterval(function() {
  13. if(j &lt;= countArray.length){
  14.   var counter = 0;
  15.   console.log(&quot;Count: &quot;, j);
  16.   console.log(&quot;X value: &quot;, countval());
  17. }
  18. }, 1000);

<!-- end snippet -->

答案2

得分: 1

您的脚本将如下所示：

  1. var countArray = [
  2.   "2020-14-03 11:14:48.225000",
  3.   "2020-14-03 11:14:48.226000",
  4.   "2020-14-03 11:14:48.227000",
  5.   "2020-14-03 11:14:48.228000",
  6.   "2020-14-03 11:14:48.229000",
  7.   "2020-14-03 11:14:48.230000",
  8.   "2020-14-03 11:14:48.231000",
  9.   "2020-14-03 11:14:48.232000",
  10.   "2020-14-03 11:14:48.233000",
  11.   "2020-14-03 11:14:48.234000",
  12.   "2020-14-03 11:14:48.235000",
  13.   "2020-14-03 11:14:48.236000",
  14.   "2020-14-03 11:14:48.237000",
  15.   "2020-14-03 11:14:48.238000",
  16.   "2020-14-03 11:14:48.239000",
  17.   "2020-14-03 11:14:48.240000",
  18.   "2020-14-03 11:14:48.241000",
  19.   "2020-14-03 11:14:48.242000",
  20.   "2020-14-03 11:14:48.243000",
  21.   "2020-14-03 11:14:48.244000"
  22. ];
  24. console.log(countArray.length);
  26. var j = 0;
  27. function countval() {
  28.   return countArray[j++];
  29. }
  31. setInterval(function() {
  32.   var counter = 0;
  33.   x = countval();
  34.   console.log("X value: ", x);
  35.   counter = countArray.indexOf(x);
  36.   console.log("Count: ", counter);
  37. }, 1000);

希望这有所帮助。

英文:

Your script will be like this:

  1.   var countArray = [&quot;2020-14-03 11:14:48.225000&quot;,&quot;2020-14-03 11:14:48.226000&quot;,&quot;2020-14-03 11:14:48.227000&quot;,&quot;2020-14-03 11:14:48.228000&quot;,&quot;2020-14-03 11:14:48.229000&quot;,&quot;2020-14-03 11:14:48.230000&quot;,&quot;2020-14-03 11:14:48.231000&quot;,&quot;2020-14-03 11:14:48.232000&quot;,&quot;2020-14-03 11:14:48.233000&quot;,&quot;2020-14-03 11:14:48.234000&quot;,&quot;2020-14-03 11:14:48.235000&quot;,&quot;2020-14-03 11:14:48.236000&quot;,&quot;2020-14-03 11:14:48.237000&quot;,&quot;2020-14-03 11:14:48.238000&quot;,&quot;2020-14-03 11:14:48.239000&quot;,&quot;2020-14-03 11:14:48.240000&quot;,&quot;2020-14-03 11:14:48.241000&quot;,&quot;2020-14-03 11:14:48.242000&quot;,&quot;2020-14-03 11:14:48.243000&quot;,&quot;2020-14-03 11:14:48.244000&quot;];
  3.   console.log(countArray.length) ;
  6. var j = 0;
  7.   function countval() 
  8.   {
  9.    return countArray[j++];
  10.   }
  12. setInterval(function(){
  13.   var counter = 0;
  14.   x= countval();
  15.   console.log(&quot;X value: &quot;, x);
  16.   counter=countArray.indexOf(x);
  17. console.log(&quot;Count: &quot;, counter);
  18.   }, 1000);

答案3

得分: 1

The error is quite simple. You're assigning x = countVal(); and countVal() returns a string value, so basically you're doing this: "2020-14-03 11:14:48.225000".count(); which is an incorrect statement. So, Firstly remove this line from your code. Other than that I'm having difficulty understanding what you're trying to do, from reading your question I assumed you want something like this:

  1. setInterval(function(){
  2.     if(j < countArray.length){
  3.         x = countval(); 
  4.         console.log("X value: ", x);
  5.         console.log("Count: ", j);
  6.     }
  7. }, 1000);

And if you want to show the length of each element of the array just edit your .count() to .length

英文:

The error is quite simple. You're assigning x = countVal(); and countVal() returns a string value, so basically you're doing this: &quot;2020-14-03 11:14:48.225000&quot;.count(); which is an incorrect statement. So, Firstly remove this line from your code. Other than that I'm having difficulty understanding what you're trying to do, from reading you're question I assumed you want something like this:

  1. setInterval(function(){
  2.     if(j &lt; countArray.length){
  3.         x = countval(); 
  4.         console.log(&quot;X value: &quot;, x);
  5.         console.log(&quot;Count: &quot;, j);
  6.     }
  7. }, 1000);

And if you want to show the length of each element of the array just edit your .count() to .length

huangapple
  • 本文由 发表于 2020年1月6日 14:55:12
  • 转载请务必保留本文链接：https://go.coder-hub.com/59607884.html
  • arrays
  • javascript
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