when do we need & in golang
The & symbol in Go is used to obtain the memory address of a variable. It's commonly used in the following scenarios:
- Passing by Reference: When you want to pass a variable by reference to a function rather than by value. This allows the function to modify the original variable.
```go func modifyValue(x int) { x = *x + 5 }
func main() { value := 10 modifyValue(&value) fmt.Println(value) // Output: 15 } ```
- Creating Pointers: It's used to create a pointer to a variable.
go
func main() {
value := 10
pointer := &value
fmt.Println(*pointer) // Output: 10
}
- Avoiding Copying Large Data: When dealing with large data structures like arrays or structs, using pointers can be more efficient than passing the data by value, which would create a copy of the entire structure.
```go type LargeStruct struct { // fields... }
func processLargeData(data *LargeStruct) { // processing... }
func main() { data := LargeStruct{ // initialize fields... } processLargeData(&data) } ```
In these situations, using & helps manage memory more efficiently or enables functions to work directly with the original data rather than copies.