(Go Lang) Pointers (GBEN)

Go by Example

Example

  • Like in C

package main

import "fmt"

// We’ll show how pointers work in contrast to values with 2 functions:
// zeroval and zeroptr. zeroval has an int parameter, so arguments will be
// passed to it by value. zeroval will get a copy of ival distinct from the
// one in the calling function.
func zeroval(ival int) {
  ival = 0
}

// zeroptr in contrast has an *int parameter, meaning that it takes an int
// pointer. The *iptr code in the function body then dereferences the pointer
// from its memory address to the current value at that address. Assigning a
// value to a dereferenced pointer changes the value at the referenced
// address.
func zeroptr(iptr *int) {
  *iptr = 0
}

func main() {
  i := 1
  fmt.Println("initial:", i)
  zeroval(i)
  fmt.Println("zeroval:", i)
  // The &i syntax gives the memory address of i, i.e. a pointer to i.
  zeroptr(&i)
  fmt.Println("zeroptr:", i)
  // Pointers can be printed too.
  fmt.Println("pointer:", &i)
}
initial: 1
zeroval: 1
zeroptr: 0
pointer: 0xc42000e2d8

Attribution


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