Getting the size of an array in an object

Question

I would like some help with getting the size of an array inside an object:

var st = { "itema":{...},"itemb":[{"id":"s01","cd":"c01","dd":"d01",....}{"id":"s02","cd":"c02","dd":"d02",....}]}

How would you get a count of the objects inside "itemb" (in this case 2)?

Answer 1

Javascript arrays have a length property. Use it like this:

st.itemb.length

Answer 2

Arrays have a property .length that returns the number of elements.

var st =
    {
        "itema":{},
        "itemb":
        [
            {"id":"s01","cd":"c01","dd":"d01"},
            {"id":"s02","cd":"c02","dd":"d02"}
        ]
    };

st.itemb.length // 2