Javascript difference between objects. keywords: compare objects, levenshtein, flatten objects

gistfile1.js

var flattenObject = function(ob) {
    var toReturn = {};

    for (var i in ob) {
        if (!ob.hasOwnProperty(i)) continue;

        if ((typeof ob[i]) == 'object') {
            var flatObject = flattenObject(ob[i]);
            for (var x in flatObject) {
                if (!flatObject.hasOwnProperty(x)) continue;

                toReturn[i + '.' + x] = flatObject[x];
            }
        } else {
            toReturn[i] = ob[i];
        }
    }
    return toReturn;
};

function levenshtein(s1, s2) {
      // http://kevin.vanzonneveld.net
      // +            original by: Carlos R. L. Rodrigues (http://www.jsfromhell.com)
      // +            bugfixed by: Onno Marsman
      // +             revised by: Andrea Giammarchi (http://webreflection.blogspot.com)
      // + reimplemented by: Brett Zamir (http://brett-zamir.me)
      // + reimplemented by: Alexander M Beedie
      // *                example 1: levenshtein('Kevin van Zonneveld', 'Kevin van Sommeveld');
      // *                returns 1: 3

    if (s1 == s2) {
        return 0;
    }

    var s1_len = s1.length;
    var s2_len = s2.length;
    if (s1_len === 0) {
        return s2_len;
    }
    if (s2_len === 0) {
        return s1_len;
    }

    // BEGIN STATIC
    var split = false;
    try{
        split=!('0')[0];
    } catch (e){
        split=true; // Earlier IE may not support access by string index
    }
    // END STATIC
    if (split){
        s1 = s1.split('');
        s2 = s2.split('');
    }

    var v0 = new Array(s1_len+1);
    var v1 = new Array(s1_len+1);

    var s1_idx=0, s2_idx=0, cost=0;
    for (s1_idx=0; s1_idx<s1_len+1; s1_idx++) {
        v0[s1_idx] = s1_idx;
    }
    var char_s1='', char_s2='';
    for (s2_idx=1; s2_idx<=s2_len; s2_idx++) {
        v1[0] = s2_idx;
        char_s2 = s2[s2_idx - 1];

        for (s1_idx=0; s1_idx<s1_len;s1_idx++) {
            char_s1 = s1[s1_idx];
            cost = (char_s1 == char_s2) ? 0 : 1;
            var m_min = v0[s1_idx+1] + 1;
            var b = v1[s1_idx] + 1;
            var c = v0[s1_idx] + cost;
            if (b < m_min) {
                m_min = b; }
            if (c < m_min) {
                m_min = c; }
            v1[s1_idx+1] = m_min;
        }
        var v_tmp = v0;
        v0 = v1;
        v1 = v_tmp;
    }
    return v0[s1_len];
}

function difference(template, override) {
    template = flattenObject(template);
    override = flattenObject(override);
    var diff = 0;
    for (var name in template) {
        if (!(name in override)){
            diff += levenshtein(template[name]+"", "");
        }
        else if (template[name] != override[name]) {
            diff += levenshtein(template[name]+"", override[name]+"");
        }
    }
    return diff;
}

var a = {a:'c',b:22,c:{d:1},k:[1,2,3,4,5,6]};
var b = {a:'c',b:23,c:{d:12119},k:[{l:22},2]};

console.log(flattenObject(a))
console.log(flattenObject(b))
    
console.log(difference(a,b));



    
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