So, Basically what I want is to get unique data from a 2d array where I can pass multiple column values which I have stored in an array. Like I want to get unique based on column 1 and 2 so, I can pass the column value like an array [0, 1] to the function and based on the column array it should return unique value.

I have tried something like this:

function sortFunction(a, b) {
  if (a[0] === b[0]) {  // 0 for column one
    return 0;
  }
  else {
    return (a[0] < b[0]) ? -1 : 1;
  }
}

function getUniqueData_(arr) {
  arr = arr.sort(sortFunction)

  let prevEl;
  const newArr = arr.reduce((prevArr, currentVal) => {
    const idx = prevArr.findIndex(val => val[0] === currentVal[0]);
    if (idx === -1) {
      if (prevEl && prevEl[0] !== currentVal[0]) {
        prevArr.push(currentVal);
      }
    } else {
      prevArr.splice(idx, 1);
    }
    prevEl = currentVal;
    return prevArr;

  }, [])

  console.log(newArr);
  return newArr;
}

Instead of passing column value manually I want to pass it dynamically and multiple columns at the same time which I have stored it in array like [0,1] for column 1 and 2.

CodePudding user response：

function sortData(){
  var columns = [0,2]
  var data = [[1,2,3],[1,2,2],[1,2,3]]
  var temp_arr = [];
  var unique_arr = [];
  var specific_columns_data = getSpecificColumnsData(data, columns)
  for(var i=0;i<specific_columns_data.length;i  ){
    if(specific_columns_data[i].join("")!==""){
      
      if(temp_arr.indexOf(specific_columns_data[i].join(""))==-1){
        unique_arr.push(data[i]);
      }
      temp_arr.push(specific_columns_data[i].join(""))
    }
  }
  Logger.log(unique_arr)
}
function getSpecificColumnsData(data, columns){
  var specific_columns_data = []
  var temp_arr = []
  for(var i=0;i<data.length;i  ){
    temp_arr = []
    for(var j = 0;j<columns.length;j  ){
      if(data[i][j]){
        temp_arr.push(data[i][columns[j]])
      }
    }
    specific_columns_data.push([temp_arr])
  }
  return specific_columns_data;
}

CodePudding user response：

To filter an array to only include specified columns, then filter the results into only unique rows,

Try:

function getUniqueData(arr) {

  const data = /*Your (array of) data to filter*/
  
  // Replace arr values with relevant row data.
  let result = arr.map(col => data.map(row => row[col]))
  // Transpose rows to columns.
  result = result[0].map((col, index) => result.flatMap(row => row[index]))
 
  // Keep only unique rows.
  return [...new Set(
    result.map(JSON.stringify)
  )].map(JSON.parse)

}

The big takeaway is the final block of the code, which is:

• Converting each row of the array into a string for comparison with JSON.stringify.
• Removing all duplicates by using new Set() with it's results 'spread' into a new array.
• Then converting all values back to their original types using JSON.parse.