From 69f9c74bcb35b146e2fa5b7115abc192685d6d71 Mon Sep 17 00:00:00 2001
From: yunxuan <yunxuanhao@gmail.com>
Date: Tue, 10 Sep 2024 15:08:36 +0800
Subject: [PATCH] feat(maputil): add GetValue (#243)

* add maputil.GetValue

* rename GetOrDefault
---
 docs/api/packages/maputil.md    | 41 +++++++++++++++++++++++++++++++++
 docs/en/api/packages/maputil.md | 41 +++++++++++++++++++++++++++++++++
 maputil/map.go                  |  9 ++++++++
 maputil/map_test.go             | 19 +++++++++++++++
 4 files changed, 110 insertions(+)

diff --git a/docs/api/packages/maputil.md b/docs/api/packages/maputil.md
index d0510c0..b4bc9f2 100644
--- a/docs/api/packages/maputil.md
+++ b/docs/api/packages/maputil.md
@@ -77,6 +77,7 @@ import (
 -   [ConcurrentMap_Range](#ConcurrentMap_Range)
 -   [GetOrSet](#GetOrSet)
 -   [SortByKey](#SortByKey)
+-   [GetOrDefault](#GetOrDefault)
 
 
 <div STYLE="page-break-after: always;"></div>
@@ -2263,4 +2264,44 @@ func main() {
     // Output:
     // map[1:a 2:b 3:c 4:d]
 }
+```
+
+### <span id="GetOrDefault">GetOrDefault</span>
+
+<p>返回给定键的值，如果键不存在，则返回默认值。</p>
+
+<b>函数签名:</b>
+
+```go
+func GetOrDefault[K comparable, V any](m map[K]V, key K, defaultValue V) V 
+```
+
+<b>示例:<span style="float:right;display:inline-block;">[运行](https://go.dev/play/p/99QjSYSBdiM)</span></b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[int]string{
+        3: "c",
+        1: "a",
+        4: "d",
+        2: "b",
+    }
+
+    result1 := maputil.GetOrDefault(m, 1, "default")
+    result2 := maputil.GetOrDefault(m, 6, "default")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // a
+    // default
+}
 ```
\ No newline at end of file
diff --git a/docs/en/api/packages/maputil.md b/docs/en/api/packages/maputil.md
index 71f97e0..6c84405 100644
--- a/docs/en/api/packages/maputil.md
+++ b/docs/en/api/packages/maputil.md
@@ -77,6 +77,7 @@ import (
 -   [ConcurrentMap_Has](#ConcurrentMap_Has)
 -   [ConcurrentMap_Range](#ConcurrentMap_Range)
 -   [GetOrSet](#GetOrSet)
+-   [GetOrDefault](#GetOrDefault)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -2279,4 +2280,44 @@ func main() {
     // Output:
     // map[1:a 2:b 3:c 4:d]
 }
+```
+
+### <span id="GetOrDefault">GetOrDefault</span>
+
+<p>returns the value of the given key or a default value if the key is not present.</p>
+
+<b>Signature:</b>
+
+```go
+func GetOrDefault[K comparable, V any](m map[K]V, key K, defaultValue V) V 
+```
+
+<b>Example:<span style="float:right;display:inline-block;">[运行](https://go.dev/play/p/99QjSYSBdiM)</span></b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[int]string{
+        3: "c",
+        1: "a",
+        4: "d",
+        2: "b",
+    }
+
+    result1 := maputil.GetOrDefault(m, 1, "default")
+    result2 := maputil.GetOrDefault(m, 6, "default")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // a
+    // default
+}
 ```
\ No newline at end of file
diff --git a/maputil/map.go b/maputil/map.go
index b70edbc..4f1fbf5 100644
--- a/maputil/map.go
+++ b/maputil/map.go
@@ -657,3 +657,12 @@ func convertMap(src reflect.Value, dst reflect.Value) error {
 
 	return nil
 }
+
+// GetOrDefault returns the value of the given key or a default value if the key is not present.
+// Play: https://go.dev/play/p/99QjSYSBdiM
+func GetOrDefault[K comparable, V any](m map[K]V, key K, defaultValue V) V {
+	if v, ok := m[key]; ok {
+		return v
+	}
+	return defaultValue
+}
diff --git a/maputil/map_test.go b/maputil/map_test.go
index a78b818..4a6c5f2 100644
--- a/maputil/map_test.go
+++ b/maputil/map_test.go
@@ -869,3 +869,22 @@ func TestBaseType(t *testing.T) {
 	MapTo(tc["u64"], &number)
 	assert.EqualValues(64, number)
 }
+
+func TestGetOrDefault(t *testing.T) {
+
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "GetOrDefault")
+
+	m1 := map[int]string{
+		3: "c",
+		1: "a",
+		4: "d",
+		2: "b",
+	}
+	result1 := GetOrDefault(m1, 1, "123")
+	assert.Equal("a", result1)
+
+	result2 := GetOrDefault(m1, 5, "123")
+	assert.Equal("123", result2)
+}