[рони]

iBoolat,
или obj[item]

var obj = {
    a: 3,
    b: 2,
    c: {
        d: 1,
        e: 2,
        f: {
            g: 1,
            h: 2
        }
    },
    i: {
        j: 1,
        k: 1
    },
    l: 1,
    m: {
        n: 1,
        o: 2,
        p: 3,
        r: {
            s: 1,
            t: 2
        },
        u: 1
    },
    v: 1,
    w: 1,
    x: {
        y: {
            z: 1
        }
    }
};

function recursion(obj) {
    for (var item in obj)
        if (typeof obj[item] === "object") {
            console.log("Here is an object!");
            recursion(obj[item])
        } else console.log(obj[item])
}
console.log(typeof obj.c);
recursion(obj);