How to Sort this type of Array

JavaScript
1

Hello,

I’m writing a javascript program where I’m counting the number of occurrences of each character in a string.

For example “hello world”:

    charArray['h'] = 1;
charArray['e'] = 1;
charArray['l'] = 3;
charArray['o'] = 2;
charArray['w'] = 1;
charArray['r'] = 1;
charArray['d'] = 1;
charArray[''] = 1;

Is there a way to sort this array by the number values in descending order? Writing a custom sort() doesn’t seem to work with string indexes. Perhaps I should store the information in a different format? Two-Dimensional array?

Any help is greatly appreciated.

Thanks.

2

I would normally have a second array of the letters in you charArray for example

indxCharArray[0] = ‘h’
indxCharArray[1] = ‘e’
indxCharArray[2] = ‘l’
indxCharArray[3] = ‘o’
indxCharArray[4] = ‘w’
indxCharArray[5] = ‘o’
indxCharArray[6] = ‘r’
indxCharArray[7] = ‘d’
indxCharArray[8] = ’ ’

and then sort that array based on the value of charArray[indxCharArray[i]]

3

This is a bit much for ‘hello world’, I admit, but maybe you have longer strings.

function charcount(s, ci){
	if(ci) s= s.toLowerCase();	// optional
	s= s.replace(/[^a-zA-Z]+/g,''); // optional
	var a= s.split('').sort(), b= [], tem, count;
	while(a.length){
		tem= a.shift();
		count= 1;
		while(a[0]== tem){
			++count;
			a.shift();
		}
		if(!b[count]) b[count]= [count];
		b[count].push(tem);
	}
	for(var i= 0, L= b.length; i<L; i++){
		tem= b[i];
		if(tem) a.push(tem.shift()+': '+tem.join(', '));
	}
	return a.sort(function(a, b){
		return parseInt(b)-parseInt(a);
	});
}

//test
var s= "hello world";
alert('Character count\
\	'+charcount(s, true).join('\
\	'))

/*  returned value: 
Character count
	3: l
	2: o
	1: d, e, h, r, w
*/