loop in js nested object

function abc(z) { for(y in z) { console.log(y, typeof z[y], z[y]); if(typeof z[y] === 'object') { abc(z[y]); } } }

function abc(z, prop) { for(y in z) { if(typeof prop === 'undefined') { console.log(y, typeof z[y], z[y]); } else { if(y === prop) { console.log('FOUND'); } } if(typeof z[y] === 'object') { abc(z[y], prop); } } }