# Slice Package slice implements some functions to manipulate slice.
## Source: - [https://github.com/duke-git/lancet/blob/main/slice/slice.go](https://github.com/duke-git/lancet/blob/main/slice/slice.go) ## Usage: ```go import ( "github.com/duke-git/lancet/v2/slice" ) ``` ## Index - [Contain](#Contain) - [ContainSubSlice](#ContainSubSlice) - [Chunk](#Chunk) - [Compact](#Compact) - [Concat](#Concat) - [Count](#Count) - [Difference](#Difference) - [DifferenceBy](#DifferenceBy) - [DifferenceWith](#DifferenceWith) - [DeleteAt](#DeleteAt) - [Drop](#Drop) - [Equal](#Equal) - [EqualWith](#EqualWith) - [Every](#Every) - [Filter](#Filter) - [Find](#Find) - [FindLast](#FindLast) - [FlattenDeep](#FlattenDeep) - [ForEach](#ForEach) - [GroupBy](#GroupBy) - [GroupWith](#GroupWith) - [IntSlice](#IntSlice) - [InterfaceSlice](#InterfaceSlice) - [Intersection](#Intersection) - [InsertAt](#InsertAt) - [IndexOf](#IndexOf) - [LastIndexOf](#LastIndexOf) - [Map](#Map) - [Reverse](#Reverse) - [Reduce](#Reduce) - [Shuffle](#Shuffle) - [SortByField](#SortByField) - [Some](#Some) - [StringSlice](#StringSlice) - [SymmetricDifference](#SymmetricDifference) - [Unique](#Unique) - [UniqueBy](#UniqueBy) - [Union](#Union) - [UpdateAt](#UpdateAt) - [Without](#Without) ## Documentation ### ContainCheck if the value is in the slice or not.
Signature: ```go func Contain[T comparable](slice []T, value T) bool ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { res := slice.Contain([]string{"a", "b", "c"}, "a") fmt.Println(res) //true } ``` ### ContainSubSliceCheck if the slice contain subslice or not.
Signature: ```go func ContainSubSlice[T comparable](slice, subslice []T) bool ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { res := slice.ContainSubSlice([]string{"a", "b", "c"}, []string{"a", "b"}) fmt.Println(res) //true } ``` ### ChunkCreates an slice of elements split into groups the length of `size`.
Signature: ```go func Chunk[T any](slice []T, size int) [][]T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { arr := []string{"a", "b", "c", "d", "e"} res := slice.Chunk(InterfaceSlice(arr), 3) fmt.Println(res) //[][]any{{"a", "b", "c"}, {"d", "e"}} } ``` ### CompactCreates an slice with all falsey values removed. The values false, nil, 0, and "" are falsey.
Signature: ```go func Compact[T any](slice []T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { res := slice.Compact([]int{0, 1, 2, 3}) fmt.Println(res) //[]int{1, 2, 3} } ``` ### ConcatCreates a new slice concatenating slice with any additional slices and/or values.
Signature: ```go func Concat[T any](slice []T, values ...[]T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { res1 := slice.Concat([]int{1, 2, 3}, 4, 5) fmt.Println(res1) //[]int{1, 2, 3, 4, 5} res2 := slice.Concat([]int{1, 2, 3}, []int{4, 5}) fmt.Println(res2) //[]int{1, 2, 3, 4, 5} } ``` ### CountCount iterates over elements of slice, returns a count of all matched elements.
Signature: ```go func Count[T any](slice []T, predicate func(index int, t T) bool) int ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 4, 5, 6} evenFunc := func(i, num int) bool { return (num % 2) == 0 } res := slice.Count(nums, evenFunc) fmt.Println(res) //3 } ``` ### DifferenceCreates an slice of whose element not included in the other given slice.
Signature: ```go func Difference[T comparable](slice, comparedSlice []T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { s1 := []int{1, 2, 3, 4, 5} s2 := []int{4, 5, 6} res := slice.Difference(s1, s2) fmt.Println(res) //[]int{1, 2, 3} } ``` ### DifferenceByDifferenceBy accepts iteratee func which is invoked for each element of slice and values to generate the criterion by which they're compared.
Signature: ```go func DifferenceBy[T comparable](slice []T, comparedSlice []T, iteratee func(index int, item T) T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { s1 := []int{1, 2, 3, 4, 5} s2 := []int{4, 5, 6} addOne := func(i int, v int) int { return v + 1 } res := slice.DifferenceBy(s1, s2, addOne) fmt.Println(res) //[]int{1, 2} } ``` ### DifferenceWithDifferenceWith accepts comparator which is invoked to compare elements of slice to values. The order and references of result values are determined by the first slice.
Signature: ```go func DifferenceWith[T any](slice []T, comparedSlice []T, comparator func(value, otherValue T) bool) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { s1 := []int{1, 2, 3, 4, 5} s2 := []int{4, 5, 6, 7, 8} isDouble := func(v1, v2 int) bool { return v2 == 2*v1 } res := slice.DifferenceWith(s1, s2, isDouble) fmt.Println(res) //[]int{1, 5} } ``` ### DeleteAtDelete the element of slice from start index to end index - 1.
Signature: ```go func DeleteAt[T any](slice []T, start int, end ...int) ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { res1 := slice.DeleteAt([]string{"a", "b", "c", "d", "e"}, 3) fmt.Println(res1) //[]string{"a", "b", "c", "e"} res2 := slice.DeleteAt([]string{"a", "b", "c", "d", "e"}, 0, 2) fmt.Println(res2) //[]string{"c", "d", "e"} } ``` ### DropCreates a slice with `n` elements dropped from the beginning when n > 0, or `n` elements dropped from the ending when n < 0.
Signature: ```go func Drop[T any](slice []T, n int) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { res1 := slice.Drop([]int{}, 0) fmt.Println(res1) //[]int{} res2 := slice.Drop([]int{1, 2, 3, 4, 5}, 1) fmt.Println(res2) //[]int{2, 3, 4, 5} res3 := slice.Drop([]int{1, 2, 3, 4, 5}, -1) fmt.Println(res3) //[]int{1, 2, 3, 4} } ``` ### EqualCheck if two slices are equal: the same length and all elements' order and value are equal.
Signature: ```go func Equal[T comparable](slice1, slice2 []T) bool ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { slice1 := []int{1, 2, 3} slice2 := []int{1, 2, 3} slice3 := []int{3, 2, 1} res1 := slice.Equal(slice1, slice2) res2 := slice.Equal(slice1, slice3) fmt.Println(res1) //true fmt.Println(res2) //false } ``` ### EqualWithCheck if two slices are equal with comparator func.
Signature: ```go func EqualWith[T, U any](slice1 []T, slice2 []U, comparator func(T, U) bool) bool ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { slice1 := []int{1, 2, 3} slice2 := []int{2, 4, 6} isDouble := func(a, b int) bool { return b == a*2 } res := slice.EqualWith(slice1, slice2, isDouble) fmt.Println(res) //true } ``` ### EveryReturn true if all of the values in the slice pass the predicate function.
Signature: ```go func Every[T any](slice []T, predicate func(index int, item T) bool) bool ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 5} isEven := func(i, num int) bool { return num%2 == 0 } res := slice.Every(nums, isEven) fmt.Println(res) //false } ``` ### FilterReturn all elements which match the function.
Signature: ```go func Filter[T any](slice []T, predicate func(index int, item T) bool) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 5} isEven := func(i, num int) bool { return num%2 == 0 } res := slice.Filter(nums, isEven) fmt.Println(res) //[]int{2, 4} } ``` ### FindIterates over elements of slice, returning the first one that passes a truth test on function.
Signature: ```go func Find[T any](slice []T, predicate func(index int, item T) bool) (*T, bool) ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 5} isEven := func(i, num int) bool { return num%2 == 0 } res, ok := slice.Find(nums, even) fmt.Println(res) //2 fmt.Println(ok) //true } ``` ### FindLastiterates over elements of slice from end to begin, returning the last one that passes a truth test on function.
Signature: ```go func FindLast[T any](slice []T, predicate func(index int, item T) bool) (*T, bool) ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 5} isEven := func(i, num int) bool { return num%2 == 0 } res, ok := slice.FindLast(nums, even) fmt.Println(res) //4 fmt.Println(ok) //true } ``` ### FlattenDeepflattens slice recursive.
Signature: ```go func FlattenDeep(slice any) any ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { arr := [][][]string{{{"a", "b"}}, {{"c", "d"}}} res := slice.FlattenDeep(arr) fmt.Println(res) //[]string{"a", "b", "c", "d"} } ``` ### ForEachIterates over elements of slice and invokes function for each element.
Signature: ```go func ForEach[T any](slice []T, iteratee func(index int, item T)) ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { numbers := []int{1, 2, 3, 4, 5} var numbersAddTwo []int slice.ForEach(numbers, func(index int, value int) { numbersAddTwo = append(numbersAddTwo, value+2) }) fmt.Println(numbersAddTwo) //[]int{3, 4, 5, 6, 7} } ``` ### GroupByIterates over elements of the slice, each element will be group by criteria, returns two slices.
Signature: ```go func GroupBy[T any](slice []T, groupFn func(index int, item T) bool) ([]T, []T) ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 4, 5, 6} evenFunc := func(i, num int) bool { return (num % 2) == 0 } even, odd := slice.GroupBy(nums, evenFunc) fmt.Println(even) //[]int{2, 4, 6} fmt.Println(odd) //]int{1, 3, 5} } ``` ### GroupWithReturn a map composed of keys generated from the results of running each element of slice thru iteratee.
Signature: ```go func GroupWith[T any, U comparable](slice []T, iteratee func(T) U) map[U][]T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []float64{6.1, 4.2, 6.3} floor := func(num float64) float64 { return math.Floor(num) } res := slice.GroupWith(nums, floor) fmt.Println(res) //map[float64][]float64{ 4: {4.2}, 6: {6.1, 6.3},} } ``` ### IntSliceConvert interface slice to int slice.
Signature: ```go func IntSlice(slice any) []int ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { var nums = []any{1, 2, 3} res := slice.IntSlice(nums) fmt.Println(res) //[]int{1, 2, 3} } ``` ### InterfaceSliceConvert value to interface slice.
Signature: ```go func InterfaceSlice(slice any) []any ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { var nums = []int{}{1, 2, 3} res := slice.InterfaceSlice(nums) fmt.Println(res) //[]any{1, 2, 3} } ``` ### IntersectionCreates a slice of unique values that included by all slices.
Signature: ```go func Intersection[T comparable](slices ...[]T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { s1 := []int{1, 2, 2, 3} s2 := []int{1, 2, 3, 4} res := slice.Intersection(s1, s2), fmt.Println(res) //[]int{1, 2, 3} } ``` ### InsertAtinsert the element into slice at index.
Signature: ```go func InsertAt[T any](slice []T, index int, value any) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { s := []string{"a", "b", "c"} res1, _ := slice.InsertAt(s, 0, "1") fmt.Println(res1) //[]string{"1", "a", "b", "c"} res2, _ := slice.InsertAt(s, 3, []string{"1", "2", "3"}) fmt.Println(res2) //[]string{"a", "b", "c", "1", "2", "3"} } ``` ### IndexOfReturns the index at which the first occurrence of a value is found in a slice or return -1 if the value cannot be found.
Signature: ```go func IndexOf[T comparable](slice []T, value T) int ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { arr := []string{"a", "a", "b", "c"} res1 := slice.IndexOf(arr, "a") fmt.Println(res1) //0 res2 := slice.IndexOf(arr, "d") fmt.Println(res2) //-1 } ``` ### LastIndexOfReturns the index at which the last occurrence of a value is found in a slice or return -1 if the value cannot be found.
Signature: ```go func LastIndexOf[T comparable](slice []T, value T) int ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { arr := []string{"a", "a", "b", "c"} res1 := slice.LastIndexOf(arr, "a") fmt.Println(res1) //1 res2 := slice.LastIndexOf(arr, "d") fmt.Println(res2) //-1 } ``` ### MapCreates an slice of values by running each element in slice thru function.
Signature: ```go func Map[T any, U any](slice []T, iteratee func(index int, item T) U) []U ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 4} multiplyTwo := func(i, num int) int { return num * 2 } res := slice.Map(nums, multiplyTwo) fmt.Println(res) //[]int{2, 4, 6, 8} } ``` ### ReverseReverse the elements order in slice.
Signature: ```go func Reverse[T any](slice []T) ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 4} slice.Reverse(nums) fmt.Println(res) //[]int{4, 3, 2, 1} } ``` ### ReduceReduce slice.
Signature: ```go func Reduce[T any](slice []T, iteratee func(index int, item1, item2 T) T, initial T) T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 4} reduceFunc := func(i, v1, v2 int) int { return v1 + v2 } res := slice.Reduce(nums, reduceFunc, 0) fmt.Println(res) //10 } ``` ### ShuffleCreates an slice of shuffled values.
Signature: ```go func Shuffle[T any](slice []T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 4, 5} res := slice.Shuffle(nums) fmt.Println(res) //3,1,5,4,2 } ``` ### SortByFieldSort struct slice by field. Slice element should be struct, field type should be int, uint, string, or bool. Default sort type is ascending (asc), if descending order, set sortType to desc
Signature: ```go func SortByField(slice any, field string, sortType ...string) error ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { type student struct { name string age int } students := []student{ {"a", 10}, {"b", 15}, {"c", 5}, {"d", 6}, } err := slice.SortByField(students, "age", "desc") if err != nil { fmt.Println(err) } fmt.Println(students) // []students{ // {"b", 15}, // {"a", 10}, // {"d", 6}, // {"c", 5}, // } } ``` ### SomeReturn true if any of the values in the list pass the predicate function.
Signature: ```go func Some[T any](slice []T, predicate func(index int, item T) bool) bool ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { nums := []int{1, 2, 3, 5} isEven := func(i, num int) bool { return num%2 == 0 } res := slice.Some(nums, isEven) fmt.Println(res) //true } ``` ### StringSliceConvert interface slice to string slice.
Signature: ```go func StringSlice(slice any) []string ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { var s = []any{"a", "b", "c"} res := slice.StringSlice(s) fmt.Println(res) //[]string{"a", "b", "c"} } ``` ### SymmetricDifferenceCreate a slice whose element is in given slices, but not in both slices.
Signature: ```go func SymmetricDifference[T comparable](slices ...[]T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { s1 := []int{1, 2, 3} s2 := []int{1, 2, 4} s3 := []int{1, 2, 3, 5} fmt.Println(slice.SymmetricDifference(s1)) //[]int{1, 2, 3} fmt.Println(slice.SymmetricDifference(s1, s2)) //[]int{3, 4} fmt.Println(slice.SymmetricDifference(s1, s2, s3)) //[]int{3, 4, 5} } ``` ### ToSliceReturns a slices of a variable parameter transformation
Signature: ```go func ToSlice[T any](value ...T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { res := slice.ToSlice("a", "b") fmt.Println(res) //{"a", "b"} } ``` ### ToSliceReturns a pointer to the slices of a variable parameter transformation
Signature: ```go func ToSlicePointer[T any](value ...T) []*T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { str1 := "a" str2 := "b" res := slice.ToSlicePointer(str1, str2) fmt.Println(res) // res -> []*string{&str1, &str2} } ``` ### UniqueRemove duplicate elements in slice.
Signature: ```go func Unique[T comparable](slice []T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { res := slice.Unique([]int{1, 2, 2, 3}) fmt.Println(res) //[]int{1, 2, 3} } ``` ### UniqueByCall iteratee func with every item of slice, then remove duplicated.
Signature: ```go func UniqueBy[T comparable](slice []T, iteratee func(item T) T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/slice" ) func main() { res := slice.UniqueBy([]int{1, 2, 3, 4, 5, 6}, func(val int) int { return val % 4 }) fmt.Println(res) //[]int{1, 2, 3, 0} } ``` ### UnionCreates a slice of unique values, in order, from all given slices. using == for equality comparisons.
Signature: ```go func Union[T comparable](slices ...[]T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { s1 := []int{1, 3, 4, 6} s2 := []int{1, 2, 5, 6} res := slice.Union(s1, s2) fmt.Println(res) //[]int{1, 3, 4, 6, 2, 5} } ``` ### UpdateAtUpdate the slice element at index. if param index < 0 or index >= len(slice), will return error.
Signature: ```go func UpdateAt[T any](slice []T, index int, value T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { s := []string{"a", "b", "c"} res1, _ := slice.UpdateAt(s, 0, "1") fmt.Println(res1) //[]string{"1", "b", "c"} } ``` ### WithoutCreates a slice excluding all given values.
Signature: ```go func Without[T comparable](slice []T, values ...T) []T ``` Example: ```go import ( "fmt" "github.com/duke-git/lancet/v2/slice" ) func main() { res := slice.Without([]int{1, 2, 3, 4, 5}, 1, 2) fmt.Println(res) //[]int{3, 4, 5} } ```