CODEWITHSUNDEEP
javascriptarrays
zeth
zeth

Reputation: 235

removing strings from array with conditions

I'm trying to write function in javascript for removing strings from array. Array is dynamically created and from time to time I add new strings to it. When I remove strings from it I first check if string is really in it.

I have one additional condition. If string that is gonna be removed is equal for example to 'bicycle' than I want to also check for 'motorbike' and if it exists remove it also. And if string given is 'motorbike' I want to remove possible occurences of 'bicycle'.

So far I have something like this:

options_array = []

function remove_option(option) {
  var option_index = options_array.indexOf(option);
  if(option_index != -1)
    options_array.splice(option_index, 1);
  if(option == 'bicycle') {
    option_index = options_array.indexOf('motorbike');
    if(option_index != -1)
      options_array.splice(option_index, 1);
  } else if(option == 'motorbike') {
    option_index = options_array.indexOf('bicycle');
    if(option_index != -1)
      options_array.splice(option_index, 1);
  }
}

It works but is it possible to make it nicer and more DRY?

Upvotes: 1

Views: 163

Answers (4)

mcgrailm
mcgrailm

Reputation: 17640

You can use and alias array and loop through them

var options_array = ["motorbike",'bicycle','bike','car','vanagon'];

function remove_option(option,alias_array) {
    var option_index = options_array.indexOf(option);
    if(option_index != -1){
        if(alias_array.indexOf(option) != -1){
            for (var i=0;i<alias_array.length;i++){ 
                alias_index = options_array.indexOf(alias_array[i]);
                if(alias_index != -1){
                    options_array.splice(alias_index, 1);
                }   
            }
        }
    }
    return options_array;
}

console.log(remove_option('bike',['motorbike','bicycle','bike']));

Upvotes: 0

laconbass
laconbass

Reputation: 17815

See Array.prototype.filter reference on mozilla developers network

Please note that Array.filter needs a ECMAScript 5th edition compilant environment.

Example implementations

1. Reassing the options_array value

var options_array = [ 'foo', 'bar', 'baz', 'bicycle', 'motorbike' ];

options_array = options_array.filter(function(value){
  return value == 'bicycle';
});
// options_array is now [ 'foo', 'bar', 'baz', 'motorbike' ]

2. Reusable function to do the same as example #1

var options_array = [ 'foo', 'bar', 'baz', 'bicycle', 'motorbike' ];

function remove_option( option_name ){
  options_array = options_array.filter(function(value){
    return value == 'bicycle';
  });
}

remove_option( 'bicycle' );
// options_array is now [ 'foo', 'bar', 'baz', 'motorbike' ]
remove_option( 'foo' );
// options_array is now [ 'bar', 'baz', 'motorbike' ]

3. Reusable function to do the same as example #2 but with any array

var options_array = [ 'foo', 'bar', 'baz', 'bicycle', 'motorbike' ];
var options_array2 = [ 'foo', 'bar', 'baz' ];

function remove_option( options_array, option_name ){
  options_array = options_array.filter(function(value){
    return value == 'bicycle';
  });
}

remove_option( options_array, 'bicycle' );
// options_array is now [ 'foo', 'bar', 'baz', 'motorbike' ]
remove_option( options_array2, 'foo' );
// options_array2 is now [ 'bar', 'baz', 'bicycle', 'motorbike' ]

You could even build an object prototype to manage option arrays if its need, but i think the examples are enought.

Upvotes: 1

musefan
musefan

Reputation: 48415

How about using an array of synonyms for each word:

var synonyms = [
    ['bicycle', 'motorbike'],
    ['car', 'van']
];

Then you can get the matching list with a helper function:

//this will return an array of related words (e.g. ['bicycle', 'motorbike'])
function getSynonyms(item) {
    for (var i = 0; i < synonyms.length; i++) {
        var arr = synonyms[i];
        for (var j = 0; j < arr.length; j++) {
            if (arr[j] == item) return arr;
        }
    }
    return null;
}

and finally your remove function can be changed like so:

//this will remove the option plus any matching synonym words
function remove_option(option) {
    var synonymsToRemove = getSynonyms(option);
    //check if any matches found, if not then just used the single specified option
    if (!synonymsToRemove) synonymsToRemove = [option];

    for (var i = 0; i < synonymsToRemove.length; i++) {
        var option_index = options_array.indexOf(synonymsToRemove[i]);
        if (option_index != -1) {
            options_array.splice(option_index, 1);
        }
    }
}

Which you can use like so:

console.log(options_array);//["bicycle", "motorbike", "car", "van"]
remove_option('bicycle');//remove 'bicycle' and related words (i.e. 'motorbike')
console.log(options_array);//["car", "van"]

Here is a working example

Upvotes: 0

Arun P Johny
Arun P Johny

Reputation: 388316

Try

options_array = []

//this can be enhanced to support multiple elements like 'motorbike, tricycle'
var related = {
    'bicycle': 'motorbike',
    'motorbike': 'bicycle'
}

function remove_option(option) {
    remove_opts(option)
    var relation = related[option];
    if (relation) {
        remove_opts(relation)
    }
}

function remove_opts(option){
    var option_index = options_array.indexOf(option);
    if (option_index != -1) options_array.splice(option_index, 1);
}

Upvotes: 0

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