var  data = [
{ catNumber: 'EK-21200',
quantity: 5},
{ catNumber: 'EK-00341',
    quantity: 5},
{ catNumber: 'EK-21200',
    quantity: 5},
{ catNumber: 'EK-21200',
    quantity: 5},
{ catNumber: 'EK-00341',
    quantity: 5}

var  data = [
{ catNumber: 'EK-21200',
quantity: 15},
{ catNumber: 'EK-00341',
    quantity: 10}