shadcn-ui/apps/v4/examples/base/select-multiple.tsx

import {
  Select,
  SelectContent,
  SelectGroup,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/examples/base/ui/select"

export function SelectMultiple() {
  const items = [
    { label: "Apple", value: "apple" },
    { label: "Banana", value: "banana" },
    { label: "Blueberry", value: "blueberry" },
    { label: "Grapes", value: "grapes" },
    { label: "Pineapple", value: "pineapple" },
    { label: "Strawberry", value: "strawberry" },
    { label: "Watermelon", value: "watermelon" },
  ]
  return (
    <Select items={items} multiple defaultValue={[]}>
      <SelectTrigger className="w-72">
        <SelectValue>
          {(value: string[]) => {
            if (value.length === 0) {
              return "Select fruits"
            }
            if (value.length === 1) {
              return items.find((item) => item.value === value[0])?.label
            }
            return `${value.length} fruits selected`
          }}
        </SelectValue>
      </SelectTrigger>
      <SelectContent>
        <SelectGroup>
          {items.map((item) => (
            <SelectItem key={item.value} value={item.value}>
              {item.label}
            </SelectItem>
          ))}
        </SelectGroup>
      </SelectContent>
    </Select>
  )
}