Slice

slice 包包含操作切片的方法集合。

源码:

• https://github.com/duke-git/lancet/blob/main/slice/slice.go (opens new window)

用法:

import (
    "github.com/duke-git/lancet/v2/slice"
)

文档

AppendIfAbsent

当前切片中不包含值时，将该值追加到切片中

函数签名:

func AppendIfAbsent[T comparable](slice []T, value T) []T

例子:

import (
	"fmt"
	"github.com/duke-git/lancet/v2/slice"
)

func main() {
	strs := []string{"a", "b"}
	res1 := slice.AppendIfAbsent(strs, "a")
	fmt.Println(res1) //[]string{"a", "b"}

	res2 := slice.AppendIfAbsent(strs, "cannot")
	fmt.Println(res2"}
}

Contain

判断slice是否包含value

函数签名:

func Contain[T comparable](slice []T, value T) bool

例子:

import (
	"fmt"
	"github.com/duke-git/lancet/v2/slice"
)

func main() {
	res := slice.Contain([]string{"a", "b", "c"}, "a")
	fmt.Println(res) //true
}

ContainSubSlice

判断slice是否包含subslice

函数签名:

func ContainSubSlice[T comparable](slice, subslice []T) bool

例子:

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
}

Chunk

按照size参数均分slice

函数签名:

func Chunk[T any](slice []T, size int) [][]T

例子:

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"}}
}

Compact

去除slice中的假值（false values are false, nil, 0, ""）

函数签名:

func Compact[T any](slice []T) []T

例子:

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}
}

Concat

连接values到slice中，values类型可以是切片或多个值

函数签名:

func Concat[T any](slice []T, values ...[]T) []T

例子:

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}
}

Count

遍历切片，对每个元素执行函数function. 返回符合函数返回值为true的元素的个数

函数签名:

func Count[T any](slice []T, predicate func(index int, t T) bool) int

例子:

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
}

Difference

创建一个切片，其元素不包含在另一个给定切片中

函数签名:

func Difference[T comparable](slice, comparedSlice []T) []T

例子:

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}
}

DifferenceBy

在slice和comparedSlice中的每个元素调用iteratee函数，并比较它们的返回值，如果不想等返回在slice中对应的值

函数签名:

func DifferenceBy[T comparable](slice []T, comparedSlice []T, iteratee func(index int, item T) T) []T

例子:

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}
}

DifferenceWith

DifferenceWith 接受比较器，该比较器被调用以将切片的元素与值进行比较。 结果值的顺序和引用由第一个切片确定

函数签名:

func DifferenceWith[T any](slice []T, comparedSlice []T, comparator func(value, otherValue T) bool) []T

例子:

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}
}

DeleteAt

删除切片中从开始索引到结束索引-1的元素

函数签名:

func DeleteAt[T any](slice []T, start int, end ...int)

例子:

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"}

}

Drop

创建一个切片，当 n > 0 时从开头删除 n 个元素，或者当 n < 0 时从结尾删除 n 个元素

函数签名:

func Drop[T any](slice []T, n int) []T

例子:

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}
}

Every

如果切片中的所有值都通过谓词函数，则返回true。 函数签名应该是func(index int, value any) bool

函数签名:

func Every[T any](slice []T, predicate func(index int, item T) bool) bool

例子:

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
}

Equal

检查两个切片是否相等，相等条件：切片长度相同，元素顺序和值都相同

函数签名:

func Equal[T comparable](slice1, slice2 []T) bool

例子:

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
}

EqualWith

检查两个切片是否相等，相等条件：对两个切片的元素调用比较函数comparator，返回true

函数签名:

func EqualWith[T, U any](slice1 []T, slice2 []U, comparator func(T, U) bool) bool

例子:

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
}

Filter

返回切片中通过predicate函数真值测试的所有元素

函数签名:

func Filter[T any](slice []T, predicate func(index int, item T) bool) []T

例子:

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}
}

Find

遍历切片的元素，返回第一个通过predicate函数真值测试的元素

函数签名:

func Find[T any](slice []T, predicate func(index int, item T) bool) (*T, bool)

例子:

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
}

FindLast

从头到尾遍历slice的元素，返回最后一个通过predicate函数真值测试的元素。

函数签名:

func FindLast[T any](slice []T, predicate func(index int, item T) bool) (*T, bool)

例子:

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
}

Flatten

将切片压平一层

函数签名:

func Flatten(slice any) any

例子:

import (
	"fmt"
	"github.com/duke-git/lancet/v2/slice"
)

func main() {
	arr := [][][]string{{{"a", "b"}}, {{"c", "d"}}}
	res := slice.Flatten(arr)
	fmt.Println(res) //{{"a", "b"}, {"c", "d"}}
}

FlattenDeep

flattens slice recursive.

函数签名:

func FlattenDeep(slice any) any

例子:

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"}
}

ForEach

遍历切片的元素并为每个元素调用iteratee函数

函数签名:

func ForEach[T any](slice []T, iteratee func(index int, item T))

例子:

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}
}

GroupBy

迭代切片的元素，每个元素将按条件分组，返回两个切片

函数签名:

func GroupBy[T any](slice []T, groupFn func(index int, item T) bool) ([]T, []T)

例子:

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}
}

GroupWith

创建一个map，key是iteratee遍历slice中的每个元素返回的结果。 分组值的顺序是由他们出现在slice中的顺序确定的。每个键对应的值负责生成key的元素组成的数组。iteratee调用1个参数： (value)

函数签名:

func GroupWith[T any, U comparable](slice []T, iteratee func(T) U) map[U][]T

例子:

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},}
}

IntSlice

将接口切片转换为int切片

函数签名:

func IntSlice(slice any) []int

例子:

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}
}

InterfaceSlice

将值转换为接口切片

函数签名:

func InterfaceSlice(slice any) []any

例子:

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}
}

Intersection

多个切片的交集

函数签名:

func Intersection[T comparable](slices ...[]T) []T

例子:

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}
}

InsertAt

将元素插入到索引处的切片中

函数签名:

func InsertAt[T any](slice []T, index int, value any) []T

例子:

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"}
}

IndexOf

返回在切片中找到值的第一个匹配项的索引，如果找不到值，则返回-1

函数签名:

func IndexOf[T comparable](slice []T, value T) int

例子:

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
}

LastIndexOf

返回在切片中找到最后一个值的索引，如果找不到该值，则返回-1

函数签名:

func LastIndexOf[T comparable](slice []T, value T) int

例子:

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
}

Map

通过运行函数slice中的每个元素来创建一个新切片

函数签名:

func Map[T any, U any](slice []T, iteratee func(index int, item T) U) []U

例子:

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}
}

Reverse

反转切片中的元素顺序

函数签名:

func Reverse[T any](slice []T)

例子:

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}
}

Reduce

将切片中的元素依次运行iteratee函数，返回运行结果

函数签名:

func Reduce[T any](slice []T, iteratee func(index int, item1, item2 T) T, initial T) T

例子:

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
}

Shuffle

随机打乱切片中的元素顺序

函数签名:

func Shuffle[T any](slice []T) []T

例子:

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
}

SortByField

按字段对结构切片进行排序。slice元素应为struct，字段类型应为int、uint、string或bool。 默认排序类型是升序（asc），如果是降序，设置 sortType 为 desc

函数签名:

func SortByField(slice any, field string, sortType ...string) error

例子:

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},
	// }
}

Some

如果列表中的任何值通过谓词函数，则返回true

函数签名:

func Some[T any](slice []T, predicate func(index int, item T) bool) bool

例子:

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
}

StringSlice

将接口切片转换为字符串切片

函数签名:

func StringSlice(slice any) []string

例子:

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"}
}

SymmetricDifference

返回一个切片，其中的元素存在于参数切片中，但不同时存储在于参数切片中（交集取反）

函数签名:

func SymmetricDifference[T comparable](slices ...[]T) []T

例子:

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}
}

ToSlice

将可变参数转为切片

函数签名:

func ToSlice[T any](value ...T) []T

例子:

import (
	"fmt"
	"github.com/duke-git/lancet/v2/slice"
)

func main() {
	res := slice.ToSlice("a", "b")
	fmt.Println(res) //{"a", "b"}
}

ToSlicePointer

将可变参数转为指针切片

函数签名:

func ToSlicePointer[T any](value ...T) []*T

例子:

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}
}

Unique

删除切片中的重复元素

函数签名:

func Unique[T comparable](slice []T) []T

例子:

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}
}

UniqueBy

对切片的每个元素调用iteratee函数，然后删除重复元素

函数签名:

func UniqueBy[T comparable](slice []T, iteratee func(item T) T) []T

例子:

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}
}

Union

从所有给定的切片按顺序创建一个唯一值切片，使用==进行相等比较

函数签名:

func Union[T comparable](slices ...[]T) []T

例子:

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}
}

UpdateAt

更新索引处的切片元素。 如果index < 0或 index >= len(slice)，将返回错误

函数签名:

func UpdateAt[T any](slice []T, index int, value T) []T

例子:

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"}
}

Without

创建一个不包括所有给定值的切片

函数签名:

func Without[T comparable](slice []T, values ...T) []T

例子:

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}
}