go - String pointers -

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consider following program (http://play.golang.org/p/ibastvudte):

package main  import (     "fmt" )  func changestringvaluenotok(dest *string, src string) {     dest = &src }  func changestringvalueok(dest *string, src string) {     *dest = src }  func main() {      := "hello"     b := "world"      changestringvaluenotok(&a, b)     fmt.println(a) // still "hello"      changestringvalueok(&a, b)     fmt.println(a) // "world" }

my goal call function , change value of string. works fine second function, not first.

question: meaning of *dest = src compared dest = &src? guess former "the contents of dest src" , latter "change dest variable points address of src" discards previous value, not contents of a. if right, don't understand how *dest = src works.

i hope question isn't fuzzy.

*dest = src

is: set value pointed @ dest value in src. it's effective.

dest = &src

is: set value of dest address of src. dest formal parameter of changestringvaluenotok change (to pointer only, not pointee) visible locally. changed value not used, it's total effect no operation.


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