How to know at what level a child is in deeply nested object?

Question

I have recursive function which prints every child in a deeply nested object.

 const tree = { name: "Anand", children: [ { name: "Dashrath", children: [ { name: "Sitesh", children: [ { name: "Yadnesh", children: [] } ] } ] }, { name: "Machindra", children: [ { name: "Tejas", children: [ { name: "Tanishka", children: [] } ], }, { name: "Amol", children: [], }, { name: "Amit", children: [] } ] } ] } function printTree(t) { if (t.children.length === 0) { return } t.children.forEach((child,index) => { console.log(child.name); printTree(child); }) } printTree(tree);

output : dashrath, sitesh, yadnesh, machindra, tanishka, amol, amit

and I want something like this 1st gen dashrath, 2nd gen sitesh, 3rd gen yadnesh, 1st gen machindra, 2nd gen tejas, 3rd gen tanishka, 2nd gen amol, 3rd gen amit

Answer 1

You could have the printTree function accept a depth parameter and increment it appropriately with each recursive call, something like this:

function printTree(t, depth = 0) {
    if (t.children.length === 0) {
        return
    }
    t.children.forEach((child,index) => {
        // you'd need to do some extra formatting here if you
        // want ordinals like "1st", "2nd", etc.
        console.log(`gen ${depth + 1}: ${child.name}`);                
        printTree(child, depth + 1);
    })
}
printTree(tree);