Pass by Reference

By default, Go passes variables to functions by value, meaning the function receives a copy of the data. Pointers allow us to pass variables by reference.

Value vs. Reference

// Pass by Value (Copy)
func incrementValue(x int) {
    x++ // only increments the local copy
}

// Pass by Reference (Original)
func incrementPointer(x *int) {
    *x++ // increments the original value
}

Pointer Fields in Structs

When working with a pointer to a struct, Go provides syntactic sugar to access fields directly using the dot operator. You don’t need to manually dereference the struct first.

type User struct {
    Name string
}

func updateName(u *User) {
    // Both are valid, but the second is preferred
    (*u).Name = "Bob"
    u.Name = "Alice" 
}

When to use?

Use pointers when:

1. You need to modify the original variable.
2. The data structure is very large, and you want to avoid the cost of copying it (though this is often less of an issue than beginners expect).