SOURCE

    //校验是否重复
    let lotBarcode = 111;
    let count = 0;
    let A = [
        {
            data:[{
                lotBarcode:111,
            }]//C层
        },//B层
        {
            data:[{
                lotBarcode:111,
            }]
        }

    ];
    for (const B of A) {
        for (const C of B.data) {
            if (C.LotBarcode == lotBarcode) {
                count++;
                if (count >= 2) {
                    console.log('已重复：'+count+'次')
                    return;
                }
            }
        }
    }