diff --git a/database/gdb/gdb.go b/database/gdb/gdb.go
index c6da50bba..89f02b799 100644
--- a/database/gdb/gdb.go
+++ b/database/gdb/gdb.go
@@ -384,9 +384,9 @@ const (
 type queryType int
 
 const (
-	queryTypeNormal queryType = 0
-	queryTypeCount  queryType = 1
-	queryTypeValue  queryType = 2
+	queryTypeNormal queryType = iota
+	queryTypeCount
+	queryTypeValue
 )
 
 type joinOperator string
@@ -400,14 +400,17 @@ const (
 type InsertOption int
 
 const (
-	InsertOptionDefault        InsertOption = 0
-	InsertOptionReplace        InsertOption = 1
-	InsertOptionSave           InsertOption = 2
-	InsertOptionIgnore         InsertOption = 3
-	InsertOperationInsert                   = "INSERT"
-	InsertOperationReplace                  = "REPLACE"
-	InsertOperationIgnore                   = "INSERT IGNORE"
-	InsertOnDuplicateKeyUpdate              = "ON DUPLICATE KEY UPDATE"
+	InsertOptionDefault InsertOption = iota
+	InsertOptionReplace
+	InsertOptionSave
+	InsertOptionIgnore
+)
+
+const (
+	InsertOperationInsert      = "INSERT"
+	InsertOperationReplace     = "REPLACE"
+	InsertOperationIgnore      = "INSERT IGNORE"
+	InsertOnDuplicateKeyUpdate = "ON DUPLICATE KEY UPDATE"
 )
 
 const (
diff --git a/net/ghttp/ghttp_request_param.go b/net/ghttp/ghttp_request_param.go
index cf232c4d7..20f67d2ef 100644
--- a/net/ghttp/ghttp_request_param.go
+++ b/net/ghttp/ghttp_request_param.go
@@ -30,9 +30,9 @@ import (
 )
 
 const (
-	parseTypeRequest = 0
-	parseTypeQuery   = 1
-	parseTypeForm    = 2
+	parseTypeRequest = iota
+	parseTypeQuery
+	parseTypeForm
 )
 
 var (
diff --git a/net/ghttp/ghttp_server_config.go b/net/ghttp/ghttp_server_config.go
index 4d3355f7b..22163051e 100644
--- a/net/ghttp/ghttp_server_config.go
+++ b/net/ghttp/ghttp_server_config.go
@@ -33,10 +33,14 @@ import (
 const (
 	defaultHttpAddr  = ":80"  // Default listening port for HTTP.
 	defaultHttpsAddr = ":443" // Default listening port for HTTPS.
-	UriTypeDefault   = 0      // Method names to the URI converting type, which converts name to its lower case and joins the words using char '-'.
-	UriTypeFullName  = 1      // Method names to the URI converting type, which does not convert to the method name.
-	UriTypeAllLower  = 2      // Method names to the URI converting type, which converts name to its lower case.
-	UriTypeCamel     = 3      // Method names to the URI converting type, which converts name to its camel case.
+
+)
+
+const (
+	UriTypeDefault  = iota // Method names to the URI converting type, which converts name to its lower case and joins the words using char '-'.
+	UriTypeFullName        // Method names to the URI converting type, which does not convert to the method name.
+	UriTypeAllLower        // Method names to the URI converting type, which converts name to its lower case.
+	UriTypeCamel           // Method names to the URI converting type, which converts name to its camel case.
 )
 
 // ServerConfig is the HTTP Server configuration manager.
diff --git a/net/gtcp/gtcp_conn_pkg.go b/net/gtcp/gtcp_conn_pkg.go
index 0be97faec..797baa92e 100644
--- a/net/gtcp/gtcp_conn_pkg.go
+++ b/net/gtcp/gtcp_conn_pkg.go
@@ -15,8 +15,9 @@ import (
 )
 
 const (
-	pkgHeaderSizeDefault = 2 // Header size for simple package protocol.
-	pkgHeaderSizeMax     = 4 // Max header size for simple package protocol.
+	_                    = iota << 1
+	pkgHeaderSizeDefault // Header size for simple package protocol.
+	pkgHeaderSizeMax     // Max header size for simple package protocol.
 )
 
 // PkgOption is package option for simple protocol.
diff --git a/net/gtcp/gtcp_pool.go b/net/gtcp/gtcp_pool.go
index eac95212a..5d4135bb6 100644
--- a/net/gtcp/gtcp_pool.go
+++ b/net/gtcp/gtcp_pool.go
@@ -21,11 +21,12 @@ type PoolConn struct {
 	status int         // Status of current connection, which is used to mark this connection usable or not.
 }
 
+const defaultPoolExpire = 10 * time.Second // Default TTL for connection in the pool.
+
 const (
-	defaultPoolExpire = 10 * time.Second // Default TTL for connection in the pool.
-	connStatusUnknown = 0                // Means it is unknown it's connective or not.
-	connStatusActive  = 1                // Means it is now connective.
-	connStatusError   = 2                // Means it should be closed and removed from pool.
+	connStatusUnknown = iota // Means it is unknown it's connective or not.
+	connStatusActive         // Means it is now connective.
+	connStatusError          // Means it should be closed and removed from pool.
 )
 
 var (