go by example part 2

5-go-by-example/17-pointers.go

@@ -0,0 +1,33 @@
+package main
+
+import "fmt"
+
+// Go supports pointers, allowing you to pass references to values and records within your program
+
+// 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 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)
+
+	// &i syntax gives the memory address
+	zeroptr(&i)
+	fmt.Println("zeroptr:", i)
+
+	// Pointers can be printed
+	fmt.Println("pointer:", &i)
+}