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Im assuming you already have Go up and running, if not make sure to do that first.

Lets start with a very simple application that simply takes a value and runs a calculation on it.

Create a new file and call it: example.gopackage main

import "fmt"

func updateValue(val int) {

val = val + 100

}

func main() {

val := 1000

updateValue(val)

fmt.Println("val:" val)

}

If you run this code like so:

! go run eample.go

The results will e:

100

0

!ou might have e"pected the output to have een1100however you need to keep in mind

that y default when you pass an argument to a function in Go it will e copied y value. Thissimply means a #copy$ of thevalvariale is used y the updateValuefunction.

Lets fi" this so that updateValuewill change thevalvalue. In order to do this we need to

pass thevalvariale y reference. That is, we will pass in the address of thevalvariale and

then updateValuecan change that value.

package main

import "fmt"

func updateValue(#omeVal $int #omeVal% $&oat') {

$#omeVal = $#omeVal + 100

$#omeVal% = $#omeVal% + 1.*

}func main() {

val := 1000

val% := ne(&oat')

updateValue(,val val%)

fmt.Println("val:" val)

http://www.giantflyingsaucer.com/blog/?p=4649http://www.giantflyingsaucer.com/blog/?p=4649

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fmt.Println("val%:" $val%)

}

The results will e:

val: 1100

val%: 1.*Lets kick this up a it and add in a struct. %e will create a struct to hold a stocks high, low

and closing market price.

&ere is the code:

package main

import "fmt"

t-pe tock #truct {

/ig/ &oat'

lo &oat' clo#e &oat'

}

func main() {

goog := tock{*. %1.01 *.%}

fmt.Println("2riginal tock 3ata:" goog)

}

The results will e:

2riginal tock 3ata: {*. %1.01 *.%}

'asy enough. (ow, we will modify the contents of thestockstruct.package main

import "fmt"

t-pe tock #truct {

/ig/ &oat'

lo &oat'

clo#e &oat'

}

func modif-tock(#tock $tock) {

#tock./ig/ = *.10

#tock.lo = 00.1*

#tock.clo#e = *0.*

}

func main() {

goog := tock{*. %1.01 *.%}

fmt.Println("2riginal tock 3ata:" goog)

http://tour.golang.org/#25http://tour.golang.org/#25

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modif-tock(,goog)

fmt.Println("4odi5ed tock 3ata:" goog)

}

The results will e:

2riginal tock 3ata: {*. %1.01 *.%}

4odi5ed tock 3ata: {*.1 00.1* *0.*}