(x) => x > 0

{"a":1,"b":"2","c":3,"d":"4","e":5,"f":6,"g":{"a":1}}

(x) => typeof x === "string"

[-1,[-1,-1,5,-1,10],-1,[-1],[-5]]

(x) => x > 0

[[[[5]]]]

(x) => Array.isArray(x)