diff --git a/README.md b/README.md
index 053750bb..9f66dd76 100644
--- a/README.md
+++ b/README.md
@@ -750,9 +750,12 @@ See the [detail information](https://github.com/gin-gonic/gin/issues/742#issueco
 ```go
 package main
 
-import "log"
-import "github.com/gin-gonic/gin"
-import "time"
+import (
+	"log"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
 
 type Person struct {
 	Name     string    `form:"name"`
diff --git a/context.go b/context.go
index 6d80284e..063c72f0 100644
--- a/context.go
+++ b/context.go
@@ -665,9 +665,9 @@ func (c *Context) Status(code int) {
 func (c *Context) Header(key, value string) {
 	if value == "" {
 		c.Writer.Header().Del(key)
-	} else {
-		c.Writer.Header().Set(key, value)
+		return
 	}
+	c.Writer.Header().Set(key, value)
 }
 
 // GetHeader returns value from request headers.
@@ -755,9 +755,9 @@ func (c *Context) JSONP(code int, obj interface{}) {
 	callback := c.DefaultQuery("callback", "")
 	if callback == "" {
 		c.Render(code, render.JSON{Data: obj})
-	} else {
-		c.Render(code, render.JsonpJSON{Callback: callback, Data: obj})
+		return
 	}
+	c.Render(code, render.JsonpJSON{Callback: callback, Data: obj})
 }
 
 // JSON serializes the given struct as JSON into the response body.
diff --git a/json/jsoniter.go b/json/jsoniter.go
index ffe1424a..f1ed5bea 100644
--- a/json/jsoniter.go
+++ b/json/jsoniter.go
@@ -13,4 +13,5 @@ var (
 	Marshal       = json.Marshal
 	MarshalIndent = json.MarshalIndent
 	NewDecoder    = json.NewDecoder
+	NewEncoder    = json.NewEncoder
 )
diff --git a/render/json.go b/render/json.go
index 6e5089a0..4d1857f5 100644
--- a/render/json.go
+++ b/render/json.go
@@ -128,10 +128,8 @@ func (r AsciiJSON) Render(w http.ResponseWriter) (err error) {
 
 	var buffer bytes.Buffer
 	for _, r := range string(ret) {
-		cvt := ""
-		if r < 128 {
-			cvt = string(r)
-		} else {
+		cvt := string(r)
+		if r >= 128 {
 			cvt = fmt.Sprintf("\\u%04x", int64(r))
 		}
 		buffer.WriteString(cvt)