使用 javascript 在 FOR 循环中选择批次的百分比

Question

I am working with javascript and i have a loop that selects all the data rows.

The number of rows can be different each time and I do not want to select ALL rows at a time. I want to get rows in 10% batches so performance is better.

Currently i am trying this approach but needs your suggestion is this is a right approach or if there is any better approach?

   var TenPercBatch = 0.1;

//  for (i in data) {   
     for (var i = 0; i < data.length*TenPercBatch; ++i) {
       var row = data[i];
    var emailAddress = row[0];  // First column     
    var emailSent = row[1]; // Second column

   if (emailSent != EMAIL_SENT) { // Prevents sending duplicates   

    //PRODUCTION EMAIL FORM LINK
     var url = "https://www.mysiteformurl-endpoint.com"; 
    UrlFetchApp.fetch(url + '&EMAILADDRESS=' + encodeURIComponent(emailAddress));

    AudienceList.getRange(startRow + i, 2).setValue(EMAIL_SENT);
      // Make sure the cell is updated right away in case the script is interrupted
      SpreadsheetApp.flush();
   }

}

Depending on number of rows, there are times when i get output in decimal when i calculate 10% of something manually...like 1000 rows, 10% would be 100..but if I have 5 rows, 10% would be 0.5. Is there any way to get the output in non-decimal closest number only so there are no issues in the code?

Like...if 10% is 0.5 then use 1.....if 10% is 7.5 then select 8...and so on...

Is it possible?

Another question is - How to select next 10% only? As I am looking at my loop, I am thinking it MAY always select same 10% batch.

Answer 1

In math there is a function called ceiling with always rounds non-whole numbers to the next integer, eg Math.ceil(3) == 3 and Math.ceil(3.1) == 4 .

To be safe, you best want to do something like this, although I am unsure as to why you would want to do this in general.

for(var a = 0; a < 10; a++)
{
    for(var i = Math.floor(a*data.length*0.1); i < data.length && i < Math.ceil((a+1)*data.length*0.1); i++)
    {
        //do stuff within batch
    }

    //do stuff in between batches
}

The inner loop iterates of the the a-th 10% of the data object. If you just want to iterate over the first 10% just set a to 0 instead of the outer for-loop.

Answer 2

当然可以，使用Math.ceil( )函数 :)