refactor: use for loop than for range

docs/maputil.md

@@ -43,6 +43,7 @@ import (
 -   [Merge](#Merge)
 -   [Minus](#Minus)
 -   [IsDisjoint](#IsDisjoint)
+-   [HasKey](#HasKey)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -893,7 +894,7 @@ func main() {
 
 ### <span id="IsDisjoint">IsDisjoint</span>
 
-<p>Checks two maps are disjoint if they have no keys in common</p>
+<p>Checks two maps are disjoint if they have no keys in common.</p>
 
 <b>Signature:</b>
 
@@ -937,3 +938,49 @@ func main() {
     // false
 }
 ```
+
+### <span id="HasKey">HasKey</span>
+
+<p>Checks if map has key or not. This function is used to replace the following boilerplate code:</p>
+
+```go
+_, haskey := amap["baz"];
+
+if haskey {
+    fmt.Println("map has key baz")
+}
+```
+
+<b>Signature:</b>
+
+```go
+func HasKey[K comparable, V any](m map[K]V, key K) bool
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+    }
+
+    result1 := HasKey(m, "a")
+    result2 := HasKey(m, "c")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // true
+    // false
+}
+```

docs/maputil_zh-CN.md

@@ -43,6 +43,7 @@ import (
 -   [Merge](#Merge)
 -   [Minus](#Minus)
 -   [IsDisjoint](#IsDisjoint)
+-   [HasKey](#HasKey)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -932,3 +933,49 @@ func main() {
     // false
 }
 ```
+
+### <span id="HasKey">HasKey</span>
+
+<p>检查map是否包含某个key。用于代替以下样板代码:</p>
+
+```go
+_, haskey := amap["baz"];
+
+if haskey {
+    fmt.Println("map has key baz")
+}
+```
+
+<b>函数签名:</b>
+
+```go
+func HasKey[K comparable, V any](m map[K]V, key K) bool
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+    }
+
+    result1 := HasKey(m, "a")
+    result2 := HasKey(m, "c")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // true
+    // false
+}
+```

docs/slice.md

@@ -90,6 +90,7 @@ import (
 -   [UpdateAt](#UpdateAt)
 -   [Without](#Without)
 -   [KeyBy](#KeyBy)
+-   [Join](#Join)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -2417,3 +2418,36 @@ func main() {
     // map[1:a 2:ab 3:abc]
 }
 ```
+
+### <span id="Join">Join</span>
+
+<p>Join the slice item with specify separator.</p>
+
+<b>Signature:</b>
+
+```go
+func Join[T any](s []T, separator string) string
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    nums := []int{1, 2, 3, 4, 5}
+
+    result1 := slice.Join(nums, ",")
+    result2 := slice.Join(nums, "-")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // 1,2,3,4,5
+    // 1-2-3-4-5
+}
+```

docs/slice_zh-CN.md

@@ -90,6 +90,7 @@ import (
 -   [UpdateAt](#UpdateAt)
 -   [Without](#Without)
 -   [KeyBy](#KeyBy)
+-   [Join](#Join)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -2390,7 +2391,7 @@ func main() {
 
 ### <span id="KeyBy">KeyBy</span>
 
-<p>将切片每个元素调用函数后转为map</p>
+<p>将切片每个元素调用函数后转为map。</p>
 
 <b>函数签名:</b>
 
@@ -2417,3 +2418,36 @@ func main() {
     // map[1:a 2:ab 3:abc]
 }
 ```
+
+### <span id="Join">Join</span>
+
+<p>用指定的分隔符链接切片元素。</p>
+
+<b>函数签名:</b>
+
+```go
+func Join[T any](s []T, separator string) string
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    nums := []int{1, 2, 3, 4, 5}
+
+    result1 := slice.Join(nums, ",")
+    result2 := slice.Join(nums, "-")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // 1,2,3,4,5
+    // 1-2-3-4-5
+}
+```

maputil/map.go

@@ -289,3 +289,21 @@ func MapValues[K comparable, V any, T any](m map[K]V, iteratee func(key K, value
 
 	return result
 }
+
+// HasKey checks if map has key or not.
+// This function is used to replace the following boilerplate code:
+// _, haskey := amap["baz"];
+//
+//	if haskey {
+//	   fmt.Println("map has key baz")
+//	}
+//
+// Play: todo
+func HasKey[K comparable, V any](m map[K]V, key K) bool {
+	_, haskey := m[key]
+	if haskey {
+		return true
+	}
+
+	return false
+}

maputil/map_example_test.go

@@ -433,3 +433,20 @@ func ExampleMapTo() {
 	// <nil>
 	// {Nothin 28 123456789 {test 1}}
 }
+
+func ExampleHasKey() {
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+	}
+
+	result1 := HasKey(m, "a")
+	result2 := HasKey(m, "c")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// true
+	// false
+}

maputil/map_test.go

@@ -458,3 +458,17 @@ func TestMapValues(t *testing.T) {
 
 	assert.Equal(expected, result)
 }
+
+func TestHasKey(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestHasKey")
+
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+	}
+
+	assert.Equal(true, HasKey(m, "a"))
+	assert.Equal(false, HasKey(m, "c"))
+}

slice/slice.go

@@ -9,6 +9,7 @@ import (
 	"math/rand"
 	"reflect"
 	"sort"
+	"strings"
 	"time"
 
 	"golang.org/x/exp/constraints"
@@ -436,8 +437,8 @@ func flattenRecursive(value reflect.Value, result reflect.Value) reflect.Value {
 // ForEach iterates over elements of slice and invokes function for each element.
 // Play: https://go.dev/play/p/DrPaa4YsHRF
 func ForEach[T any](slice []T, iteratee func(index int, item T)) {
-	for i, v := range slice {
-		iteratee(i, v)
+	for i := 0; i < len(slice); i++ {
+		iteratee(i, slice[i])
 	}
 }
 
@@ -445,8 +446,8 @@ func ForEach[T any](slice []T, iteratee func(index int, item T)) {
 // when iteratee return false, will break the for each loop.
 // Play: https://go.dev/play/p/qScs39f3D9W
 func ForEachWithBreak[T any](slice []T, iteratee func(index int, item T) bool) {
-	for i, v := range slice {
-		if !iteratee(i, v) {
+	for i := 0; i < len(slice); i++ {
+		if !iteratee(i, slice[i]) {
 			break
 		}
 	}
@@ -457,8 +458,8 @@ func ForEachWithBreak[T any](slice []T, iteratee func(index int, item T) bool) {
 func Map[T any, U any](slice []T, iteratee func(index int, item T) U) []U {
 	result := make([]U, len(slice), cap(slice))
 
-	for i, v := range slice {
-		result[i] = iteratee(i, v)
+	for i := 0; i < len(slice); i++ {
+		result[i] = iteratee(i, slice[i])
 	}
 
 	return result
@@ -1188,3 +1189,13 @@ func KeyBy[T any, U comparable](slice []T, iteratee func(item T) U) map[U]T {
 
 	return result
 }
+
+// Join the slice item with specify separator.
+// Play: todo
+func Join[T any](s []T, separator string) string {
+	str := Map(s, func(_ int, item T) string {
+		return fmt.Sprint(item)
+	})
+
+	return strings.Join(str, separator)
+}

slice/slice_example_test.go

@@ -1032,3 +1032,17 @@ func ExampleKeyBy() {
 	// Output:
 	// map[1:a 2:ab 3:abc]
 }
+
+func ExampleJoin() {
+	nums := []int{1, 2, 3, 4, 5}
+
+	result1 := Join(nums, ",")
+	result2 := Join(nums, "-")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// 1,2,3,4,5
+	// 1-2-3-4-5
+}

slice/slice_test.go

@@ -1161,3 +1161,17 @@ func TestRepeat(t *testing.T) {
 	assert.Equal([]string{}, Repeat("a", 0))
 	assert.Equal([]string{"a", "a", "a", "a", "a", "a"}, Repeat("a", 6))
 }
+
+func TestJoin(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestJoin")
+
+	nums := []int{1, 2, 3, 4, 5}
+
+	result1 := Join(nums, ",")
+	result2 := Join(nums, "-")
+
+	assert.Equal("1,2,3,4,5", result1)
+	assert.Equal("1-2-3-4-5", result2)
+}