starting go by example

5-go-by-example/9-slices.go

@@ -0,0 +1,60 @@
+package main
+
+import "fmt"
+
+// Slices are a key data type in Go, giving a more powerful interface to sequences than arrays
+func main() {
+
+	// slices are typed only by the elements they contain (not the number of elements)
+	// Here make a slice of strings of length 3 (initially zero-valued)
+	s := make([]string, 3)
+	fmt.Println("emp:", s)
+
+	// set and get like with arrays
+	s[0] = "a"
+	s[1] = "b"
+	s[2] = "c"
+	fmt.Println("set:", s)
+	fmt.Println("get:", s[2])
+
+	// len returns the length of the slice as expected
+	fmt.Println("len:", len(s))
+
+	// returns a slice containing one or more new values
+	s = append(s, "d")
+	s = append(s, "e", "f")
+	fmt.Println("apd:", s)
+
+	// create an empty slice c of the same length as s and copy into c from s
+	c := make([]string, len(s))
+	copy(c, s)
+	fmt.Println("cpy:", c)
+
+	// Slices support operators with the syntax slice[low:high]
+	l := s[2:5]
+	fmt.Println("sl1:", l)
+
+	// slices up to (but excluding) s[5]
+	l = s[:5]
+	fmt.Println("sl2:", l)
+
+	// slices up from (and including) s[2]
+	l = s[2:]
+	fmt.Println("sl3:", l)
+
+	// declare and initialize a variable for slice in a single line
+	t := []string{"g", "h", "i"}
+	fmt.Println("dcl:", t)
+
+	// Slices can be composed into multi-dimensional data structures
+	// The length of the inner slices can vary, unlike with multi-dimensional arrays
+	twoD := make([][]int, 3)
+	for i := 0; i < 3; i++ {
+		innerLen := i + 1
+		twoD[i] = make([]int, innerLen)
+		for j := 0; j < innerLen; j++ {
+			twoD[i][j] = i + j
+		}
+	}
+	fmt.Println("2d: ", twoD)
+}