Performance 当循环通过数百行时，如何提高速度？

我试着循环一张工作表，计算出职位的先进先出成本基础。我的工作表现在只有120行，但它无疑会随着时间的推移而增长。这个函数的执行速度已经相当慢了，所以我正在寻找如何加速它的解决方案。我也是一名noob程序员，这是我第一次使用javascript，所以任何其他建议都将不胜感激

谢谢

function FifoCostBasis(symbol, quantity) {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = ss.getSheetByName("Transactions Import");
  var lastRow = 150;
  var lastCol = 12;
  var costBasisSold = Number(0);
  var quantitySold = Number(0);


    for (var row = lastRow; row >= 2; row--){
      var action = sheet.getRange(row,2).getValue();
      var sym = sheet.getRange(row,3).getValue();
      var qSold = Number(sheet.getRange(row,5).getValue());
      var cbSold = Number(sheet.getRange(row,10).getValue());
      var price = Number(sheet.getRange(row, 6).getValue()); 

      if(["Buy", "Reinvest Shares", "Short Term Cap Gain Reinvest", 
"Qual Div Reinvest", "Long Term Cap Gain 
Reinvest"].indexOf(action)>=0
         && sym == symbol){
        quantitySold += qSold;
        costBasisSold += cbSold;

        if(quantitySold > quantity){ 
          var difference = quantitySold - quantity;
          var cbSoldAdj = difference*price;
          quantitySold = quantitySold - difference;
          costBasisSold = costBasisSold - cbSoldAdj;  
        };
      };
    };

      return costBasisSold;

};

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您应该尽量减少对getValue的调用。与其一次只获取一个值，不如下拉一个值数组

var data = sheet.getRange(2, 1, lastRow, lastCol).getValues();

这将返回一个Javascript数组对象。需要记住的一点是，Javascript数组从索引值0开始

 var row2 = data[0];  //Since we the range started at row 2, row 2 will be at position 0.
 var row2col1 = row[0][0];

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如果使用数组中的值，处理过程将快得多。

类似的方法可能适合您：

function FifoCostBasis(symbol, quantity) {
  if(symbol && quantity){
    var ss=SpreadsheetApp.getActiveSpreadsheet();
    var sh=ss.getSheetByName("Transactions Import");
    var lastRow=150;//there is a sh.getLastRow() function that might work for you
    var lastCol=12;//there is a sh.getLastColumn() function that might work for you
    var rg=sh.getRange(2,1,149,12);//row 2, column 1, num rows = 150-2+1, 12 columns
    var vA=rg.getValues();//all data for the entire sheet is acquired here
    var costBasisSold=0;
    var quantitySold=0;
    for(var i=vA.length-1;i>=0;i++){//i=0 is row 2
      var action=vA[i][1];
      var sym=vA[i][2];
      var qSold=Number(vA[i][4]);
      var dbSold=Number(vA[i][9]);
      var price=Number(vA[i][5]);
      if((["Buy","Reinvest Shares","Short Term Cap Gain Reinvest","Qual Div Reinvest","Long Term Cap Gain Reinvest"].indexOf(action)>=0) && sym==symbol){
        quantitySold += qSold;
        costBasisSold += cbSold;
      }
      if(quantitySold > quantity) { 
        var difference = quantitySold - quantity;
        var cbSoldAdj = difference*price;
        quantitySold = quantitySold - difference;
        costBasisSold = costBasisSold - cbSoldAdj;  
      }
    }
    return costBasisSold;
  }else{
    throw('Error: Invalid Inputs in function FifoCostBasis');
  }
}

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可能重复的好，我会试试这个。非常感谢。我只是做了一个小编辑。注意选择范围后对getValues的调用。