#65: Add ArrayReverse (#66)

README.md

@@ -38,6 +38,7 @@ Go library for PHP community with convenient functions
     * [ArrayMin/ArrayMax](#user-content-arrayminarraymax)
     * [ArrayUnique](#user-content-arrayunique)
     * [ArrayValues](#user-content-arrayvalues)
+    * [ArrayReverse](#user-content-arrayreverse)
     * [Range](#user-content-range)
     * [EqualSlices](#user-content-equalslices)
 * [Collections](#user-content-collections)
@@ -386,6 +387,16 @@ res = pgo.ArrayValues(map[string]int{"a": 1, "b": 2, "c": 3}) // []int{1, 2, 3}
 res = pgo.ArrayValues(map[int]float64{1: 123.33, 2: 22, 3: 123.33}) // []float64{22, 123.33, 123.33}
 ```
 
+### ArrayReverse
+
+reverse slice passed as an argument
+
+```go
+toReverse := []int{-3, 0, 4, 9, 13}
+pgo.ArrayReverse(toReverse) 
+fmt.Println(toReverse) // []int{13, 9, 4, 0, -3}
+```
+
 #### Range
 
 creates an int slice of min to max range

array.go

@@ -352,3 +352,10 @@ func ArrayValues[K, V comparable](a map[K]V) []V {
 
 	return s
 }
+
+// ArrayReverse reverse slice passed as an argument
+func ArrayReverse[V comparable](s []V) {
+	for i, j := 0, len(s)-1; i < j; i, j = i+1, j-1 {
+		s[i], s[j] = s[j], s[i]
+	}
+}

array_test.go

@@ -530,3 +530,55 @@ func TestArrayValues(t *testing.T) {
 		assert.Equal(t, res, v.res)
 	}
 }
+
+func TestArrayReverse(t *testing.T) {
+	testInts := map[string]struct {
+		toReverse []int
+		reversed  []int
+	}{
+		"ok ints": {
+			toReverse: []int{-3, 0, 4, 9, 13},
+			reversed:  []int{13, 9, 4, 0, -3},
+		},
+		"ok empty ints": {
+			toReverse: []int{},
+			reversed:  []int{},
+		},
+		"ok one ints": {
+			toReverse: []int{},
+			reversed:  []int{},
+		},
+	}
+
+	for n, tt := range testInts {
+		t.Run(n, func(t *testing.T) {
+			pgo.ArrayReverse(tt.toReverse)
+			assert.Equal(t, tt.toReverse, tt.reversed)
+		})
+	}
+
+	testStr := map[string]struct {
+		toReverse []string
+		reversed  []string
+	}{
+		"ok strings": {
+			toReverse: []string{"foo", "bar", "baz", "ipsum"},
+			reversed:  []string{"ipsum", "baz", "bar", "foo"},
+		},
+		"ok empty strings": {
+			toReverse: []string{},
+			reversed:  []string{},
+		},
+		"ok one string": {
+			toReverse: []string{"bark"},
+			reversed:  []string{"bark"},
+		},
+	}
+
+	for n, tt := range testStr {
+		t.Run(n, func(t *testing.T) {
+			pgo.ArrayReverse(tt.toReverse)
+			assert.Equal(t, tt.toReverse, tt.reversed)
+		})
+	}
+}