nil, the range expression blocks forever.
n, the iteration values 0 through n-1
-are produced in increasing order, with the same type as n.
+are produced in increasing order.
If n <= 0, the loop does not run any iterations.
-The iteration values are assigned to the respective -iteration variables as in an assignment statement. -
-
The iteration variables may be declared by the "range" clause using a form of
short variable declaration
(:=).
-In this case their types are set to the types of the respective iteration values
-and their scope is the block of the "for" statement;
-each iteration has its own separate variables [Go 1.22]
+In this case their scope is the block of the "for" statement
+and each iteration has its own new variables [Go 1.22]
(see also "for" statements with a ForClause).
-If the iteration variables are declared outside the “for” statement,
-after execution their values will be those of the last iteration.
+If the range expression is a (possibly untyped) integer expression n,
+the variable has the same type as if it was
+declared with initialization
+expression n.
+Otherwise, the variables have the types of their respective iteration values.
+
+If the iteration variables are not explicitly declared by the "range" clause,
+they must be preexisting.
+In this case, the iteration values are assigned to the respective variables
+as in an assignment statement.
+If the range expression is a (possibly untyped) integer expression n,
+n too must be assignable to the iteration variable;
+if there is no iteration variable, n must be assignable to int.
@@ -6765,6 +6772,11 @@ for i := range 10 {
// type of i is int (default type for untyped constant 10)
f(i)
}
+
+// invalid: 256 cannot be assigned to uint8
+var u uint8
+for u = range 256 {
+}