-Strings, arrays, and slices can be sliced to construct substrings or descriptors
-of subarrays. The index expressions in the slice select which elements appear
-in the result. The result has indexes starting at 0 and length equal to the
-difference in the index values in the slice. After slicing the array a
+For a string, array, or slice a, the primary expression
-a := [4]int{1, 2, 3, 4};
-s := a[1:3];
+a[lo : hi]
-the slice s has type []int, length 2, capacity 3, and elements
+constructs a substring or slice. The index expressions lo and
+hi select which elements appear in the result. The result has
+indexes starting at 0 and length equal to
+hi - lo.
+After slicing the array a
+
+a := [5]int{1, 2, 3, 4, 5};
+s := a[1:4];
+
+
+
+the slice s has type []int, length 3, capacity 4, and elements
s[0] == 2 s[1] == 3 +s[2] == 4
-The slice length must not be negative.
+For convenience, the hi expression may be omitted; the notation
+a[lo :] is shorthand for a[lo : len(a)].
For arrays or strings, the indexes
lo and hi must satisfy
0 <= lo <= hi <= length;
@@ -2461,7 +2472,7 @@ assignment of regular parameters.
func Split(s string, pos int) (string, string) {
- return s[0:pos], s[pos:len(s)]
+ return s[0:pos], s[pos:]
}
func Join(s, t string) string {
@@ -4137,7 +4148,7 @@ The memory is initialized as described in the section on initial values
(§The zero value).
-
+
new(T)
@@ -4170,7 +4181,7 @@ The memory is initialized as described in the section on initial values
(§The zero value).
-
+
make(T [, optional list of expressions])
@@ -4199,6 +4210,34 @@ m := make(map[string] int, 100); // map with initial space for 100 elements
+Copying slices
+
+
+The built-in function copy copies array or slice elements from
+a source src to a destination dst and returns the
+number of elements copied. Source and destination may overlap.
+Both arguments must have the same element type T and must be
+assignment compatible to a slice
+of type []T. The number of arguments copied is the minimum of
+len(src) and len(dst).
+
+
+
+copy(dst, src []T) int
+
+
+
+Examples:
+
+
+
+var a = [...]int{0, 1, 2, 3, 4, 5, 6, 7};
+var s = make([]int, 6);
+n1 := copy(s, &a); // n1 == 6, s == []int{0, 1, 2, 3, 4, 5}
+n2 := copy(s, s[2:]); // n2 == 4, s == []int{2, 3, 4, 5, 4, 5}
+
+
+
Bootstrapping