Recursion problem; JSON parsing

Question

I have a json object:

[{ "thing": "Top", "data": { "childs": [{ "thing": "a", "data": { "text": "sdfgdg1", "morestuff": { "thing": "Top", "data": { "childs": [{ "thing": "a", "data": { "text": "sdfg2", "morestuff": "", } }, { "thing": "a", "data": { "text": "gfhjfghj3", "morestuff": { "thing": "Top", "data": { "childs": [{ "thing": "a", "data": { "text": "asdfsadf 2 4", "morestuff": { "thing": "Top", "data": { "childs": [{ "thing": "a", "data": { "text": "asdfsadf 2 5", "morestuff": { "thing": "Top", "data": { "childs": { "thing": "a", "data": { "text": "asdfsadf 2 6", "morestuff": "", }, "data": { "text": "asdfsadf 2 6", "morestuff": "", } }, } }, } }], } }, } }], } }, } }], } }, } }, { "thing": "a", "data": { "text": "asdfasd1 2", "morestuff": { "thing": "Top", "data": { "childs": [{ "thing": "a", "data": { "text": "asdfsadf 2 3", "morestuff": "", } }], } }, } }, { "thing": "a", "data": { "text": "dfghfdgh 4", "morestuff": "", } }], } }] 

... and I'm trying to iterate over it and get the total number of text objects.

I can't seem to get something recursive. I think I lack understanding at both json and recursion level.

After several days of options:

 count=0; c2=0; c3=0; function ra(arr){ //console.log(arr.data.morestuff) if(arr!==undefined && arr.data && arr.data.morestuff===""){ c3++; }else if((arr && arr.data && typeof arr.data.morestuff==="object")){ if(arr.data.morestuff.data.childs.length>1){ for(var w=0;w<arr.data.morestuff.data.childs.length;w++){ count+=ra(arr.data.morestuff.data.childs[w]) } }else{ count+=ra(arr.data.morestuff.data.childs[0]) } } return(c3) } countn=0;//top morestuff with no morestuff tot=0; function reps(obj){ tot=obj.data.childs.length; console.log("tot="+tot) for(var x=0;x<tot;x++){ tot+=ra(obj.data.childs[x]) c3=0 if(tot>1000){//trying to prevent a runaway loop somehwere break; } } console.log(tot) } reps(json[0]); 

I came to the conclusion that I simply do not know. I get different results; some of them came closer, adding together the results from the ra method, but nothing was consistent (i.e. incorrect) and always turned off by at least a few.

JSON is consistent, although there are unknown numbers of children and children, so I am looking for recursion.

Here is the fiddle: http://jsfiddle.net/CULVx/

Ideally, I would like to count every text object, its "relative position" and the number of children that I have, but I believe that I can combine this material into an array if I could just make the count work ...

NB: I tried jsonParse and other libraries to no avail. In particular, jsonParse throws an Object has no method "match" error when trying to use it on this json.

Answer 1

If you just need all the "text" properties at any depth, that should be enough: http://jsfiddle.net/QbpqT/ .

You have a property key twice though ( "data" in the nested object itself). Since an object cannot contain two properties with the same key, it means that you really have 9 "text" properties; not 10.

 var count = 0; function iterate(obj) { for(var key in obj) { // iterate, `key` is the property key var elem = obj[key]; // `obj[key]` is the value if(key === "text") { // found "text" property count++; } if(typeof elem === "object") { // is an object (plain object or array), // so contains children iterate(elem); // call recursively } } } iterate(data); // start iterating the topmost element (`data`) console.log(count); // 9