Each Character occurrence in a string

Question

How to write a javascript code that counts each character occurrence in a string ?

e.g 
String is : Hello World 

Output :  
count of H -> 1
count of e -&         


        

Answer 1

this code should work:

var str = "Hello World";
var arr = str.split('');
var occ = {};
for(var i=0,c=arr.length;i<c;i++){
    if(occ[arr[i]]) occ[arr[i]]++;
    else occ[arr[i]] = 1;
}
for(var i in occ){
    alert('count of '+i+' -> '+occ[i]); 
}

Answer 2

var splitWord = "Hello World".split('');
var letters = {};
for(var i in splitWord)
{
    var letter = splitWord[i];
    if(letter == ' ') continue;
    if(typeof letters[letter] == 'undefined')
    {
        letters[letter] = 0;
    }
    letters[letter]++;
}
console.dir(letters);

Answer 3

var counts = {};
yourstring.split('').map(function(ch) {
  counts[ch] = (counts[ch] || 0) + 1;
});

Or be hip and use map/reduce:

var counts = yourstring.split('').reduce(function(dst, c) {
  dst[c] = (dst[c] || 0) + 1;
  return dst;
}, {});