Checking length of dictionary object [duplicate]

Question

What I do is use Object.keys() to return a list of all the keys and then get the length of that

Object.keys(dictionary).length

var c = {'a':'A', 'b':'B', 'c':'C'};
var count = 0;
for (var i in c) {
   if (c.hasOwnProperty(i)) count++;
}

alert(count);

This question is confusing. A regular object, {} doesn't have a length property unless you're intending to make your own function constructor which generates custom objects which do have it ( in which case you didn't specify ).

Meaning, you have to get the "length" by a for..in statement on the object, since length is not set, and increment a counter.

I'm confused as to why you need the length. Are you manually setting 0 on the object, or are you relying on custom string keys? eg obj['foo'] = 'bar';. If the latter, again, why the need for length?

Edit #1: Why can't you just do this?

list = [ {name:'john'}, {name:'bob'} ];

Then iterate over list? The length is already set.

Count and show keys in a dictionary (run in console):

o=[];count=0; for (i in topicNames) { ++count; o.push(count+": "+ i) } o.join("\n")

Sample output:

"1: Phase-out Left-hand
2: Define All Top Level Taxonomies But Processes
3: 987
4: 16:00
5: Identify suppliers"

Simple count function:

function size_dict(d){c=0; for (i in d) ++c; return c}