Details about how range works?

<p>So as a programmer first getting their feet wet with Golang, I&#39;m writing a simple command line blackjack program. When I was working on initializing an array of players, I was trying to set the balance of each player to start as 100 by doing the following package main import( &#34;fmt&#34; &#34;strconv&#34; dealer &#34;github.com/rcoverick/gocasino/dealer&#34; )</p> <pre><code>func main(){ //p is read from command line /*loading players */ players := make([]Player ,p+1) for _,player := range players{ player.balance = 100 } for i,player := range players{ fmt.Println(&#34;Player &#34;,i,&#34; balance: $&#34;,player.balance) } } </code></pre> <p>however, the output was as though the balance didn&#39;t get set at all for the player structs. </p> <pre><code>Number of players: 3 Player 0 balance: $ 0 Player 1 balance: $ 0 Player 2 balance: $ 0 </code></pre> <p>However, when I change the range loop to be </p> <pre><code>for i,_ := range players{ players[i].balance = 100 } </code></pre> <p>I get the expected result of </p> <pre><code>Number of players: 3 Player 0 balance: $ 100 Player 1 balance: $ 100 Player 2 balance: $ 100 </code></pre> <p>Is there something I&#39;m missing here about the range function when performed on a slice? I thought the behavior was such that the second argument returned for each iteration of the for loop was linked to the underlying structure? or are certain scenarios of using range only return a copy of the value from the underlying container?</p> <hr/>**评论：**<br/><br/>drvd: <pre><p>In </p> <pre><code>for _,player := range players </code></pre> <p>The variable player is not a &#34;reference&#34; (as Go has no concept of reference) to the individual elements of the slice players, but a new variable. Its value is a <em>copy</em> of each slice element during iteration.</p> <p>Take the Tour of Go <a href="https://tour.golang.org/" rel="nofollow">https://tour.golang.org/</a> especially Slides <a href="https://tour.golang.org/flowcontrol/1" rel="nofollow">https://tour.golang.org/flowcontrol/1</a> ff.</p></pre>codemonkey14: <pre><p>I had briefly gone through the Tour of Go but it just seemed a little weird coming from being used to foreach type of looping structures in other languages. Just wanted to make sure I was understanding it correctly. thanks for the advice!</p></pre>kostix: <pre><p>You should make yourself accustomed with the concept that in Go, just like in C, everything is passed by value (copied). This includes variable assignments -- including your case with iteration with range, which &#34;yields&#34; a pair of values on each iteration, -- and passing arguments to functions.</p> <p>When you need, you can use a pointer to explicitly pass &#34;a reference&#34; to a value around rather than the value itself. In this case a pointer value is passed around using the same rules.</p> <p>If you need to modify a slice&#39;s array&#39;s item when iterating using range, ignore the second value returned and use the indexing operator to access the slice.</p> <p>TL;DR You appear to not have too much experience with reasonably low-level programming languages, so you might get tripped again by some presumption you take for granted having had worked with more high-level PLs. So I&#39;d advise you to at least complete the tour. The &#34;Effective Go&#34; document is also recommended.</p></pre>twisted1919: <pre><p>Here&#39;s an alternative that will do what you are after, using pointers: <a href="https://play.golang.org/p/C5HXyP-m_I" rel="nofollow">https://play.golang.org/p/C5HXyP-m_I</a></p></pre>