lo/docs/data/core-countbyerr.md

name, slug, sourceRef, category, subCategory, signatures, variantHelpers, playUrl, similarHelpers, position

name	slug	sourceRef	category	subCategory	signatures	variantHelpers	playUrl	similarHelpers	position
CountByErr	countbyerr	slice.go#L863	core	slice	func CountByErr[T any](collection []T, predicate func(item T) (bool, error)) (int, error)	core#slice#countbyerr	https://go.dev/play/p/7BnyPhpG6lW	core#slice#countby core#slice#count core#slice#everybyerr core#slice#somebyerr	5

Counts the number of elements for which the predicate is true. Returns an error if the predicate function fails, stopping iteration immediately.

count, err := lo.CountByErr([]int{1, 5, 1}, func(i int) (bool, error) {
    if i == 5 {
        return false, fmt.Errorf("5 not allowed")
    }
    return i < 4, nil
})
// 0, error("5 not allowed")

count, err := lo.CountByErr([]int{1, 5, 1}, func(i int) (bool, error) {
    return i < 4, nil
})
// 2, nil