How to join javascript array elements without forloop

I have from a mongoose query result:

{
    "store": [
        {
            "items": [
                "A1",
                "A2"
            ]
        },
        {
            "items": [
                "A3",
                "A4"
            ]
        },
        {
            "items": [
                "B1",
                "B2"
            ]
        },
        {
            "items": [
                "B3",
                "B4"
            ]
        },
        {
            "items": [
                "C8",
                "C9",
                "C10"
            ]
        }
    ]
}

I need this: [“A1″,”A2″,”A3″,”A4″,”B1″,”B2″,”B3″,”B4″,”C8″,”C9”,C10]
Is there any way to do this without using foreach loop, as my array will be so long and it will be time consuming.