[
    {a: [1, 2], b: "1"}, {a: [3, 4], b: "22"}, 
    {a: [5, 3], b: 3}, {a:[3], b: 4}, {b: 5},
    {a: [3, 4], b: 2}
]
{.a[].length > 1}
{3 in .a}.{.a[].includes(4)}
{!(typeof .b === "string")}