A compound statement attached to a switch can include declarations. Due to the flow of control in a switch , however, initialization of identifiers so declared are not performed if these initializers have automatic storage duration. The integral promotions are performed on the controlling expression, and the constant expression of each case statement is converted to the promoted type. Control is transferred to the labeled case statement whose expression value matches the value of the controlling expression. If no such match occurs, control is transferred either past the end of the switch or to the labeled default statement, if one exists in the switch .
Execution continues sequentially once control has been transferred.
In particular, the flow of control is not altered upon encountering another case label. In the for statement, the second expression is the controlling expression. The second expression is the controlling expression, which is evaluated before each iteration. The third expression often specifies incrementation. It is evaluated after each iteration.