Question

I have to decompose words into collections of letters in Javascript. Then I need to be able to i) check whether a letter belongs to the collection and ii) to remove letters for this collection progressively.

For example, the word ‘cool’ would be decomposed into ‘c’, ‘o’, ‘o’, ‘l’. If I remove ‘o’, ‘a’ and ‘l’, I should be left with ‘c’, ‘o’ only.

What is the proper data structure to achieve this in Javascript?

Answer 1

A string!

var str = 'cool';

To check if a character is in the string:

if(str.indexOf('o') > -1) // the character is in the string

To remove the first occurrence of a character:

str = str.replace('o','');

If you want to modify the string object to provide more “logical” representations of these actions you could do this:

String.prototype.contains = function(char){
    return this.indexOf(char) > -1;
};
String.prototype.remove = function(char){
    return this.replace(char,'');
};

which you could use like this:

if ('cheese'.contains('che'))
   alert('Velviva!');

var str = 'hurt'.remove('r');   // 'hut'
    str = 'banana'.remove('n'); // 'baana'
    str = 'happy'.remove('c');  // 'happy'