Homework 12+ Purachai CS RMU

  const myFilter = products.filter(el =>
    el.name.toLowerCase().indexOf(filterText.toLowerCase()) !== -1 &&
    (inStockOnly ? el.stocked : true)
   )
   const finalList = myFilter.reduce((a, c) => {
    if (c.category !== a.lastCategory) {
       a.output = [...a.output,<ProductCategoryRow key={c.category} category={c.category} />]
       a.lastCategory = c.category
    }
    a.output = [...a.output, <ProductRow key={c.name} product={c} />]
    return a
   }, { lastCategory: null, output: [] })