Go language pointers

This is a creation in Article, where the information may have evolved or changed.

The go language retains the difference between the values in C and pointers, but it makes a lot of simplification for the cumbersome use of pointers, introducing the concept of references. So in the go language, you almost don't have to worry about getting all sorts of errors due to the direct manipulation of the inside inch. The go language pointer is basically left to distinguish between ByRef and ByVal semantics.

First, let's look at a simple example.

Package <textarea wrap="soft" class="crayon-plain print-no" data-settings="dblclick" readonly="" style="-moz-tab-size:4; -o-tab-size:4; -webkit-tab-size:4; tab-size:4; font-size: 12px !important; line-height: 15px !important;">Mainimport "FMT" func zeroval (ival int) {ival = 0}func zeroptr (iptr *int) {*iptr = 0}func main () {I : = 1 FMT. Println ("initial:", i) zeroval (i) fmt. Println ("Zeroval:", i) zeroptr (&i) fmt. Println ("Zeroptr:", i) pointers can be printed too. Fmt. PRINTLN ("pointer:", &i)}</textarea>

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Package MainImport "FMT"funcZeroval(ivalint) {    ival = 0}funczeroptr(Iptr *int) {    *iptr = 0}funcMain() {    I := 1    FMT.Println("initial:", I)    Zeroval(I)    FMT.Println("Zeroval:", I)    zeroptr(&I)    FMT.Println("Zeroptr:", I)Pointerscan bePrintedtoo.    FMT.Println("pointer:", &I)}

Package <textarea wrap="soft" class="crayon-plain print-no" data-settings="dblclick" readonly="" style="-moz-tab-size:4; -o-tab-size:4; -webkit-tab-size:4; tab-size:4; font-size: 12px !important; line-height: 15px !important;">Mainimport "FMT" type Test struct{Name string}func change2 (t *test) {t.name = "2"}func change3 (t *test) { Note here the parentheses//if the direct *t.name=3 compilation does not pass an error invalid indirect of t.name (type String)//actually in go inside * can be omitted, directly similar to the CHANGE2 function in this use. (*t). Name = "3"}func change4 (t Test) {t.name = "4"}func main () {//t is an address t: = &test{name: "1"} FMT. Println (T.name); Change2 (t) fmt. Println (T.name); Change3 (t) fmt. Println (T.name); Here pass the variable with the * CHANGE4 (*t) fmt. Println (t.name);}</textarea>

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Package MainImport "FMT"type Test struct{    Namestring}funcChange2(T *Test){    T.Name = "2"}funcChange3(T *Test){    //Note the parentheses here    //If direct *t.name=3 compilation does not pass error invalid indirect of t.name (type string)    //actually in go inside * can be omitted, directly similar to Change2 function in this use.     (*T).Name = "3"}funcChange4(T Test){    T.Name = "4"}funcMain() {    //t is an address    T := &Test{Name:"1"}    FMT.Println(T.Name);        Change2(T)    FMT.Println(T.Name);        Change3(T)    FMT.Println(T.Name);        //Here Pass the variable with *    Change4(*T)    FMT.Println(T.Name);}

Package <textarea wrap="soft" class="crayon-plain print-no" data-settings="dblclick" readonly="" style="-moz-tab-size:4; -o-tab-size:4; -webkit-tab-size:4; tab-size:4; font-size: 12px !important; line-height: 15px !important;">main Import "FMT" type ABC struct{v int} func (a ABC) AAAA () {//pass in the value instead of referencing A.v=1 FMT. Printf ("1:%d\n", A.V)} func (a *abc) bbbb () {//passed in is a reference, not a value of FMT. Printf ("2:%d\n", A.V) a.v=2 FMT. Printf ("3:%d\n", A.V)} func (a *abc) CCCC () {//passed in is a reference, not a value of FMT. Printf ("4:%d\n", A.V)} func main () {aobj:=abc{}//new (ABC); AOBJ.AAAA () aobj.bbbb () AOBJ.CCCC ()}</textarea>

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Package Main Import "FMT" type ABC struct{    v int} func (a ABC)AAAA(){ //Pass in a value, not a reference    a.v=1    FMT.Printf("1:%d\n",a.v)} func (A *ABC)bbbb(){ //Incoming is a reference, not a value    FMT.Printf("2:%d\n",a.v)    a.v=2    FMT.Printf("3:%d\n",a.v)} func (A *ABC)CCCC(){ //Incoming is a reference, not a value    FMT.Printf("4:%d\n",a.v)} funcMain(){    Aobj:=ABC{}  //new (ABC);    Aobj.AAAA()    Aobj.bbbb()    Aobj.CCCC()}

Go language Pointers