Writing google Javascript similar to vlookup

Question

ColumnA ColumnB
jhinz    115
tom      116 

The idea behind this code is someone enters a number (lets say 116), the computer looks it up in column B and returns the name in column A (tom)

The only part I need help on for the code is the computer looking up the value in column 116.

I was trying to do a for loop with a nested if statement but it wasn't working. Could someone help me?

Answer 1

I figured that @Serge's function can be made slightly more modular and might be worth sharing.

/*
Imitates the Vlookup function. Receives:
1. sheet - A reference to the sheet you would like to run Vlookup on
2. column - The number of the column the lookup should begin from
3. index - The number of columns the lookup should cover.
4. value - The desired value to look for in the column.
Once the cell of the [value] has been found, the returned parameter would be the value of the cell which is [index] cells to the right of the found cell.
*/
function vlookup(sheet, column, index, value) {

  var lastRow=sheet.getLastRow();
  var data=sheet.getRange(1,column,lastRow,column+index).getValues();

  for(i=0;i<data.length;++i){
    if (data[i][0]==value){
      return data[i][index];
    }
  }
}

Any suggestions or improvements are appreciated. This could also be a good opportunity to start a repo for much needed Google Sheet API functions that are missing. I started a new repo which might someday turn into something more useful, if you're up to contributing your own custom made functions, please don't hesitate to PR.

Cheers!

Answer 2

//~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`
//--//Dependent on isEmpty_()
// Script Look-up
/*
Benefit of this script is:
-That google sheets will not continually do lookups on data that is not changing with using this function as it is set with hard values until script is kicked off again.
-Unlike Vlookup you can have it look at for reference data at any Column in the row.  Does not have to be in the first column for it to work like Vlookup.
-You can return the Lookup to Memory for further processing by other functions

Useage:

var LocNum    = SpreadsheetApp.openById(SheetID).getSheetByName('Sheet1').getRange('J2:J').getValues();

Lookup_(Sheetinfo,"Sheet1!A:B",0,[1],"Sheet1!I1","n","y");
//or
Lookup_(Sheetinfo,"Sheet1!A:B",0,[1],"return","n","n");
//or
Lookup_(Sheetinfo,"Sheet1!A:B",0,[0,1],"return","n","n");
//or
Lookup_(Sheetinfo,"Sheet1!A:B",1,[0],"return","y","n");
//or
Lookup_(Sheetinfo,"Sheet1!A:G",4,[0],"Database!A1","y","y");
//or
Lookup_(Sheetinfo,LocationsArr,4,[0],"return","y","y");
*/

function Lookup_(Search_Key,RefSheetRange,SearchKey_Ref_IndexOffSet,IndexOffSetForReturn,SetSheetRange,ReturnMultiResults,Add_Note)   
{
  if(Object.prototype.toString.call(Search_Key) === '[object String]')
  {
    var Search_Key = new Array(Search_Key);
  }

  if(Object.prototype.toString.call(IndexOffSetForReturn) === '[object Number]')
  {
    var IndexOffSetForReturn = new Array(IndexOffSetForReturn.toString());
  }

  if(Object.prototype.toString.call(RefSheetRange) === '[object String]')
  {
    var RefSheetRangeArr = RefSheetRange.split("!");
    var Ref_Sheet = RefSheetRangeArr[0];
    var Ref_Range = RefSheetRangeArr[1];
    var data = SpreadsheetApp.getActive().getSheetByName(Ref_Sheet).getRange(Ref_Range).getValues();         //Syncs sheet by name and range into var
  }

  if(Object.prototype.toString.call(RefSheetRange) === '[object Array]')
  {
    var data = RefSheetRange;
  }

  if(!/^return$/i.test(SetSheetRange))
  {
  var SetSheetRangeArr = SetSheetRange.split("!");
  var Set_Sheet = SetSheetRangeArr[0];
  var Set_Range = SetSheetRangeArr[1];
  var RowVal = SpreadsheetApp.getActive().getSheetByName(Set_Sheet).getRange(Set_Range).getRow();
  var ColVal = SpreadsheetApp.getActive().getSheetByName(Set_Sheet).getRange(Set_Range).getColumn();
  }

  var twoDimensionalArray = [];
  for (var i = 0, Il=Search_Key.length; i<Il; i++)                                                         // i = number of rows to index and search  
  {
    var Sending = [];                                                                                      //Making a Blank Array
    var newArray = [];                                                                                     //Making a Blank Array
    var Found ="";
    for (var nn=0, NNL=data.length; nn<NNL; nn++)                                                                 //nn = will be the number of row that the data is found at
    {
      if(Found==1 && /^n$/i.test(ReturnMultiResults))                                                                                         //if statement for found if found = 1 it will to stop all other logic in nn loop from running
      {
        break;                                                                                             //Breaking nn loop once found
      }
      if (data[nn][SearchKey_Ref_IndexOffSet]==Search_Key[i])                                              //if statement is triggered when the search_key is found.
      {
        var newArray = [];
        for (var cc=0, CCL=IndexOffSetForReturn.length; cc<CCL; cc++)                                         //cc = numbers of columns to referance
        {
          var iosr = IndexOffSetForReturn[cc];                                                             //Loading the value of current cc
          var Sending = data[nn][iosr];                                                                    //Loading data of Level nn offset by value of cc
          if(isEmpty_(Sending))                                                                      //if statement for if one of the returned Column level cells are blank
          {
          var Sending =  "#N/A";                                                                           //Sets #N/A on all column levels that are blank
          }
          if (CCL>1)                                                                                       //if statement for multi-Column returns
          {
            newArray.push(Sending);
            if(CCL-1 == cc)                                                                                //if statement for pulling all columns into larger array
            {
              twoDimensionalArray.push(newArray);
              var Found = 1;                                                                              //Modifying found to 1 if found to stop all other logic in nn loop
              break;                                                                                      //Breaking cc loop once found
            }
          }
          else if (CCL<=1)                                                                                 //if statement for single-Column returns
          {
            twoDimensionalArray.push(Sending);
            var Found = 1;                                                                                 //Modifying found to 1 if found to stop all other logic in nn loop
            break;                                                                                         //Breaking cc loop once found
          }
        }
      }
      if(NNL-1==nn && isEmpty_(Sending))                                                             //following if statement is for if the current item in lookup array is not found.  Nessessary for data structure.
      {
        for(var na=0,NAL=IndexOffSetForReturn.length;na<NAL;na++)                                          //looping for the number of columns to place "#N/A" in to preserve data structure
        {
          if (NAL<=1)                                                                                      //checks to see if it's a single column return
          {
            var Sending = "#N/A";
            twoDimensionalArray.push(Sending);
          }
          else if (NAL>1)                                                                                  //checks to see if it's a Multi column return
          {
            var Sending = "#N/A";
            newArray.push(Sending);
          }
        }
        if (NAL>1)                                                                                         //checks to see if it's a Multi column return
        {
          twoDimensionalArray.push(newArray);  
        }
      }
    }
  }
  if(!/^return$/i.test(SetSheetRange))
  {
    if (CCL<=1)                                                                                            //checks to see if it's a single column return for running setValue
    {
      var singleArrayForm = [];
      for (var l = 0,lL=twoDimensionalArray.length; l<lL; l++)                                                          //Builds 2d Looping-Array to allow choosing of columns at a future point
      {
        singleArrayForm.push([twoDimensionalArray[l]]);
      }
      SpreadsheetApp.getActive().getSheetByName(Set_Sheet).getRange(RowVal,ColVal,singleArrayForm.length,singleArrayForm[0].length).setValues(singleArrayForm);
    }
    if (CCL>1)                                                                                             //checks to see if it's a multi column return for running setValues
    {
      SpreadsheetApp.getActive().getSheetByName(Set_Sheet).getRange(RowVal,ColVal,twoDimensionalArray.length,twoDimensionalArray[0].length).setValues(twoDimensionalArray);
    }
    if(/^y$/i.test(Add_Note))
    {
      if(Object.prototype.toString.call(RefSheetRange) === '[object Array]')
      {
        SpreadsheetApp.getActive().getSheetByName(Set_Sheet).getRange(RowVal,ColVal,1,1).setNote("VLookup Script Ran On: " + Utilities.formatDate(new Date(), "PST", "MM-dd-yyyy hh:mm a") + "\nRange: Origin Variable" );      
      }
      if(Object.prototype.toString.call(RefSheetRange) === '[object String]')
      {
        SpreadsheetApp.getActive().getSheetByName(Set_Sheet).getRange(RowVal,ColVal,1,1).setNote("VLookup Script Ran On: " + Utilities.formatDate(new Date(), "PST", "MM-dd-yyyy hh:mm a") + "\nRange: " + RefSheetRange);      
      }
    }
    SpreadsheetApp.flush();
  }
  if(/^return$/i.test(SetSheetRange))
  {
    return twoDimensionalArray
  }
}
//~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`

//~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`
// Empty String Check
function isEmpty_(string) 
{
  if(Object.prototype.toString.call(string) === '[object Boolean]') return false;

  if(!string)             return true;         
  if(string == '')        return true;
  if(string === false)    return true; 
  if(string === null)     return true; 
  if(string == undefined) return true;
  string = string+' '; // check for a bunch of whitespace
  if('' == (string.replace(/^\s\s*/, '').replace(/\s\s*$/, ''))) return true;       

  return false;        
}
//~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`~,~`

Answer 3

in its simplest form and to see the working principle you could try this :

function findinB() {
  var sh = SpreadsheetApp.getActiveSheet();
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var last=ss.getLastRow();
  var data=sh.getRange(1,1,last,2).getValues();// create an array of data from columns A and B
  var valB=Browser.inputBox('Enter value to search in B')
  for(nn=0;nn<data.length;++nn){
    if (data[nn][1]==valB){break} ;// if a match in column B is found, break the loop
      }
Browser.msgBox(data[nn][0]);// show column A
}