Initialization and use of map in golang language

// First declare the map 
var m1 map[string]string 
// Then use the make function to create a non-nil map, nil map cannot be assigned 
m1 = make(map[string]string) 
// Finally, assign 
m1[ to the declared map "a"] = "aa" 
m1["b"] = "bb" 

// Create 
m2 directly := make(map[string]string) 
// Then assign 
m2["a"] = "aa" 
m2[" b"] = "bb" 

// Integration of initialization + assignment 
m3 := map[string]string{ 
	"a": "aa", 
	"b": "bb", 
} 

// ======== ================================== 
// Find whether the key value exists 
if v, ok := m1[" a"]; ok { 
	fmt.Println(v) 
} else { 
	fmt.Println("Key Not Found") 
} 

// Traverse the map 
for k, v := range m1 { 
	fmt.Println(k, v) 
}

 

But our code is:

data := map[string]interface{}{
		"F_mobile" : 	      mf.Mobile,
		"F_certificate_code": mf.ID,
		"F_true_name":        gbkTrueName,
		"F_create_time":      timeStr,
		"F_modify_time":      timeStr,
	}

These values ​​are all of string type, why use interface?