How can I use lodash/underscore to sort by multiple nested fields?

Question

I want to do something like this:

var data = [
    {
        sortData: {a: \'a\', b: 2}
    },
    {
        sortData: {a: \'a\', b: 1}
    },
    {
        sort         


        

Answer 1

If the problem is an integer is converted to a string, add zeroes before the integer to make it have the same length as the longest in the collection:

var maxLength = _.reduce(data, function(result, item) {
    var bString = _.toString(item.sortData.b);
    return result > bString.length ? result : bString.length;            
}, 0);

_.sortBy(data, function(item) {
    var bString = _.toString(item.sortData.b);
    if(maxLength > bString.length) {
        bString = [new Array(maxLength - bString.length + 1).join('0'), bString].join('');
    }

    return [item.sortData.a, bString];
});