diff --git a/expr/expr.go b/expr/expr.go
new file mode 100644
index 0000000..f9b43ca
--- /dev/null
+++ b/expr/expr.go
@@ -0,0 +1,9 @@
+package expr
+
+// 如为真返回参数一，否则返回参数二
+func If[T any](e bool, v1, v2 T) T {
+	if e {
+		return v1
+	}
+	return v2
+}
diff --git a/expr/expr_test.go b/expr/expr_test.go
new file mode 100644
index 0000000..40873b4
--- /dev/null
+++ b/expr/expr_test.go
@@ -0,0 +1,9 @@
+package expr
+
+import "testing"
+
+func TestIf(t *testing.T) {
+	v1 := 10
+	v2 := 4
+	t.Log(If(v1 > v2, v1, v2))
+}