How to count number of keys in json?

Question

JavaScript

Json with multiple nesting levels.

names = JSON.parse(ch, function(key, value){
  var b = 0;
  if(key.length > 0){
    b = b+1;
  }
  console.log(b);
});

With this approach, in the console (chrome) you can see how many times the key length has been compared. Is it possible to extract this value somehow?
Question two)
how to jump to the third level with such a campaign

for(i in names){
    if( typeof names[i] === 'object'){
      names = names[i];
      len = len + Object.keys(names).length;
      console.log("len temp", len);	
    }
  }

Answer 1

var jsonString = "{... your json string ...}";
console.log(jsonString.match(/[^\\]":/g).length);