const arr = [ [0,1,0,1], [1,1,1,0], [0,1,1,0], [0,0,0,1] ]; function square(a){ let st = []; for(let i=0;i<a.length;i++){ for(let j=0;j<a.length;j++){ console.log('inner for:: ',i,j,a[i][j]); if(a[i][j]==0) continue; st.push(check(a,i,j,a.length)); //break; } // if(st.length>0) // break; } return st; } function check(ar,i,j,l){ let res = []; if(i+1<l && j+1<l){ if(ar[i+1][j+1]==1){ console.log('in check:: ',i+1,j+1,ar[i+1][j+1]); return check(ar,i+1,j+1,l); } res.push(i); res.push(j); return res; } return res; } console.log(square(arr));