remove value from comma separated values string

Question

I have a csv string like this "1,2,3" and want to be able to remove a desired value from it.

For example if I want to remove the value: 2, the output string should be the following:

"1,3"

I'm using the following code but seems to be ineffective.

var values = selectedvalues.split(",");
            if (values.length > 0) {
                for (var i = 0; i < values.length; i++) {
                    if (values[i] == value) {
                        index = i;
                        break;
                    }
                }
                if (index != -1) {
                    selectedvalues = selectedvalues.substring(0, index + 1) + selectedvalues.substring(index + 3);                    
                }
            }
            else {
                selectedvalues = "";
            }

Answer 1

var removeValue = function(list, value, separator) {
  separator = separator || ",";
  var values = list.split(separator);
  for(var i = 0 ; i < values.length ; i++) {
    if(values[i] == value) {
      values.splice(i, 1);
      return values.join(separator);
    }
  }
  return list;
}

If the value you're looking for is found, it's removed, and a new comma delimited list returned. If it is not found, the old list is returned.

Thanks to Grant Wagner for pointing out my code mistake and enhancement!

John Resign (jQuery, Mozilla) has a neat article about JavaScript Array Remove which you might find useful.

Answer 2

function removeValue(list, value) {
  return list.replace(new RegExp(",?" + value + ",?"), function(match) {
      var first_comma = match.charAt(0) === ',',
          second_comma;

      if (first_comma &&
          (second_comma = match.charAt(match.length - 1) === ',')) {
        return ',';
      }
      return '';
    });
};


alert(removeValue('1,2,3', '1')); // 2,3
alert(removeValue('1,2,3', '2')); // 1,3
alert(removeValue('1,2,3', '3')); // 1,2

Answer 3

Here are 2 possible solutions:

function removeValue(list, value) {
  return list.replace(new RegExp(value + ',?'), '')
}

function removeValue(list, value) {
  list = list.split(',');
  list.splice(list.indexOf(value), 1);
  return list.join(',');
}

removeValue('1,2,3', '2'); // "1,3"

Note that this will only remove first occurrence of a value.

Also note that Array.prototype.indexOf is not part of ECMAScript ed. 3 (it was introduced in JavaScript 1.6 - implemented in all modern implementations except JScript one - and is now codified in ES5).

Answer 4

values is now an array. So instead of doing the traversing yourself.

Do:

var index = values.indexOf(value);
if(index >= 0) {
    values.splice(index, 1);
}

removing a single object from a given index.

hope this helps

Answer 5

// Note that if the source is not a proper CSV string, the function will return a blank string ("").
function removeCsvVal(var source, var toRemove)      //source is a string of comma-seperated values,
{                                                    //toRemove is the CSV to remove all instances of
    var sourceArr = source.split(",");               //Split the CSV's by commas
    var toReturn  = "";                              //Declare the new string we're going to create
    for (var i = 0; i < sourceArr.length; i++)       //Check all of the elements in the array
    {
        if (sourceArr[i] != toRemove)                //If the item is not equal
            toReturn += sourceArr[i] + ",";          //add it to the return string
    }
    return toReturn.substr(0, toReturn.length - 1);  //remove trailing comma
}

To apply it too your var values:

var values = removeVsvVal(selectedvalues, "2");

Answer 6

guess im too slow but here is what i would do

<script language="javascript"> 
function Remove(value,replaceValue) 
{   var result = ","+value+",";
result = result.replace(","+replaceValue+",",",");
result = result.substr(1,result.length);
result = result.substr(0,result.length-1);
alert(result);
}

Remove("1,2,3",2)
</script>

adding , before and after the string ensure that u only remove the exact string u want

Answer 7

function process(csv,valueToDelete) {
  var tmp = ","+csv;
  tmp = tmp.replace(","+valueToDelete,"");
  if (tmp.substr(0,1) == ',') tmp = tmp.substr(1);
  return tmp;
}

Answer 8

use splice, pop or shift. depending on your requirement.

You could also have "find" the indexes of items in your array that match by using a function like the one found here : http://www.hunlock.com/blogs/Ten_Javascript_Tools_Everyone_Should_Have

var tmp = [5,9,12,18,56,1,10,42,'blue',30, 7,97,53,33,30,35,27,30,'35','Ball', 'bubble'];
//         0/1/2 /3 /4/5 /6 /7     /8  /9/10/11/12/13/14/15/16/17/  18/    19/      20
var thirty=tmp.find(30);             // Returns 9, 14, 17
var thirtyfive=tmp.find('35');       // Returns 18
var thirtyfive=tmp.find(35);         // Returns 15
var haveBlue=tmp.find('blue');       // Returns 8
var notFound=tmp.find('not there!'); // Returns false
var regexp1=tmp.find(/^b/);          // returns 8,20    (first letter starts with b)
var regexp1=tmp.find(/^b/i);         // returns 8,19,20 (same as above but ignore case)

Array.prototype.find = function(searchStr) {
  var returnArray = false;
  for (i=0; i<this.length; i++) {
    if (typeof(searchStr) == 'function') {
      if (searchStr.test(this[i])) {
        if (!returnArray) { returnArray = [] }
        returnArray.push(i);
      }
    } else {
      if (this[i]===searchStr) {
        if (!returnArray) { returnArray = [] }
        returnArray.push(i);
      }
    }
  }
  return returnArray;
}

Answer 9

or

var csv_remove_val = function(s, val, sep) { 
  var sep = sep || ",", a = s.split(sep), val = ""+val, pos;
  while ((pos = a.indexOf(val)) >= 0) a.splice(pos, 1);
  return a.join(sep);
}