Google Script/sheets - 如何使用 ...new Set() 使脚本在循环期间运行得更快

Question

Based on the great support by @ziganotschka on this question , we have the following code. For each of reference, here's a link to the demo sheet posted on the original question.

function change_row_color() {
  var spreadsheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Sheet1');
  var range = spreadsheet.getDataRange();
  var rangeData = range.getValues();
  var lastRow = spreadsheet.getLastRow();
  var previousclient = rangeData[0][4];
  console.log(previousclient);
  var colors = [[0,0,0,0,0]];
  for ( j = 1 ; j < lastRow; j++){
    var currentclient = rangeData[j][4];
    console.log(previousclient," ",currentclient);
    if (previousclient != currentclient) {
      colors.push(["#cc4125","#cc4125","#cc4125","#cc4125","#cc4125"]);
      previousclient = currentclient;  
    } else{
      colors.push([0,0,0,0,0]);
    }
  }
range.setBackgrounds(colors);
}

The script is running great, but it's running rather slow. My test array has 350 rows and it takes about 20s to run. My actual array has 10K+ rows, and growing. Once I run this code on the real array, I'd like to drop it to below 5s. ziganotschka suggested to use...new Set(). I'd love you input on this.

Answer 1

Using Conditional formatting

To apply a given style for all the row where the value in the E column is the same as the previous row.

In your sheet:

• Format > Conditional formatting
• Apply to range A2:Z
• Format rule Custom formula is
• Value of formula =$E2=$E1 // change the value of E is you need to make the test on an other row.

Choose your wanted formatting style.

Answer 2

May not be any faster but you can give it a try.

function change_row_color() {
  var ss=SpreadsheetApp.getActive()
  var sh=ss.getSheetByName('Sheet1');
  var rg=sh.getDataRange();
  var vs=rg.getValues();
  var colors=rg.getBackgrounds();
  colors.map(function(r){return r.fill('#000000')});//this is not necessary if the backgrounds always start as black.
  var pc=vs[0][4];
  vs.forEach(function(r,i){
    if(i>0 && r[4]!=pc) {
        colors[i].fill("#cc4125");
        pc=r[4];
    }
  });
rg.setBackgrounds(colors);
}