Go Naming Rules
Guidelines for naming variables and identifiers in Go
📝 Variable Naming Rules
Go has specific rules for naming variables and identifiers. Following these conventions makes your code readable, maintainable, and helps avoid compilation errors in your programs.
// Valid variable names
var userName string = "alice"
var age2 int = 25
var _temp float64 = 98.6
fmt.Println(userName, age2, _temp)
Output:
alice 25 98.6
Essential Naming Rules
Start Character
Must begin with letter or underscore
var name string ✓
var _temp int ✓Valid Characters
Letters, digits, and underscores only
var user123 string ✓
var total_sum int ✓Case Sensitive
userName and username are different
var Name string
var name stringReserved Words
Cannot use Go keywords
// var if int ✗
var condition bool ✓🔹 Valid Variable Names
Examples of correct variable naming:
// Valid names
var firstName string = "John"
var lastName string = "Doe"
var age int = 30
var user123 string = "alice"
var _privateVar int = 42
var totalAmount float64 = 1500.75
var isActive bool = true
var MAX_SIZE int = 100
fmt.Printf("User: %s %s, Age: %d\n", firstName, lastName, age)
fmt.Printf("Account: %s, Amount: $%.2f\n", user123, totalAmount)
fmt.Printf("Active: %t, Max Size: %d\n", isActive, MAX_SIZE)Output:
User: John Doe, Age: 30
Account: alice, Amount: $1500.75
Active: true, Max Size: 100
🔹 Invalid Variable Names
Examples that will cause compilation errors:
// These will NOT work - compilation errors
// var 2name string = "invalid" // Cannot start with digit
// var user-name string = "invalid" // Hyphen not allowed
// var user name string = "invalid" // Space not allowed
// var if int = 5 // 'if' is reserved keyword
// var func string = "invalid" // 'func' is reserved keyword
// Correct alternatives:
var name2 string = "valid"
var userName string = "valid"
var user_name string = "valid"
var condition int = 5
var function string = "valid"
fmt.Println("All valid names work:", name2, userName, user_name)Output:
All valid names work: valid valid valid
🔹 Go Reserved Keywords
These words cannot be used as variable names:
Go Keywords (25 total):
🔹 Naming Conventions
Best practices for Go variable naming:
// Recommended naming conventions
var userName string = "alice" // camelCase for local variables
var UserName string = "Alice" // PascalCase for exported variables
var MAX_CONNECTIONS int = 100 // UPPER_CASE for constants
var _internalVar string = "private" // underscore prefix for internal use
// Descriptive names
var customerAge int = 25
var totalPrice float64 = 199.99
var isLoggedIn bool = true
// Short names for short scope
for i := 0; i < 5; i++ {
fmt.Printf("Index: %d\n", i)
}
fmt.Printf("Customer age: %d, Price: $%.2f, Logged in: %t\n",
customerAge, totalPrice, isLoggedIn)Output:
Index: 0
Index: 1
Index: 2
Index: 3
Index: 4
Customer age: 25, Price: $199.99, Logged in: true