JavaScript recursive search in JSON object

I use the following

var searchObject = function (object, matchCallback, currentPath, result, searched) {
    currentPath = currentPath || '';
    result = result || [];
    searched = searched || [];
    if (searched.indexOf(object) !== -1 && object === Object(object)) {
        return;
    }
    searched.push(object);
    if (matchCallback(object)) {
        result.push({path: currentPath, value: object});
    }
    try {
        if (object === Object(object)) {
            for (var property in object) {
                if (property.indexOf("$") !== 0) {
                    //if (Object.prototype.hasOwnProperty.call(object, property)) {
                        searchObject(object[property], matchCallback, currentPath + "." + property, result, searched);
                    //}
                }
            }
        }
    }
    catch (e) {
        console.log(object);
        throw e;
    }
    return result;
}

Then you can write

searchObject(rootNode, function (value) { return value != null && value != undefined && value.id == '10'; });

Now this works on circular references and you can match on any field or combination of fields you like by changing the matchCallback function.

When searching recursively, you have to pass the result back by returning it. You're not returning the result of findNode(id, currentChild), though.

function findNode(id, currentNode) {
    var i,
        currentChild,
        result;

    if (id == currentNode.id) {
        return currentNode;
    } else {

        // Use a for loop instead of forEach to avoid nested functions
        // Otherwise "return" will not work properly
        for (i = 0; i < currentNode.children.length; i += 1) {
            currentChild = currentNode.children[i];

            // Search in the current child
            result = findNode(id, currentChild);

            // Return the result if the node has been found
            if (result !== false) {
                return result;
            }
        }

        // The node has not been found and we have no more options
        return false;
    }
}

function findNode(id, currentNode) {

    if (id == currentNode.id) {
        return currentNode;
    } else {
        var result;
        currentNode.children.forEach(function(node){
            if(node.id == id){
                result = node;
                return;
            }
        });
        return (result ? result : "No Node Found");
    }
}
console.log(findNode("10", node));

This method will return the node if it present in the node list. But this will loop through all the child of a node since we can't successfully break the forEach flow. A better implementation would look like below.

function findNode(id, currentNode) {

    if (id == currentNode.id) {
        return currentNode;
    } else {
        for(var index in currentNode.children){
            var node = currentNode.children[index];
            if(node.id == id)
                return node;
            findNode(id, node);
        }
        return "No Node Present";
    }
}
console.log(findNode("1", node));