Golang : How to check if slice or array is empty?

Problem :

One of your code is throwing out panic error and apparently it is trying to do a for loop on an empty slice or array.

Solution :

Check if the slice or array is empty first with the builtin len() function, such as len(slice) <= 0. If the slice or array is empty, skip the for loop.

IF you are trying to check if your SQL query returns any rows. Such as from QueryRow() function. Then check the returned error message.

For example :

 err := db.QueryRow("SELECT ...").Scan(&id, &username)
 if err == sql.ErrNoRows {
 // do your stuff
 }