
 
There may be a situation when you need to execute a block of code several number of times. In general, statements are executed sequentially: The first statement in a function is executed first, followed by the second, and so on.
Programming languages provide various control structures that allow for more complicated execution paths.
A loop statement allows us to execute a statement or group of statements multiple times. Following is the general from of a loop statement in most of the programming languages −
 
Swift 4 programming language provides the following kinds of loop to handle looping requirements. Click the following links to check their detail.
| Sr.No | Loop Type & Description | 
|---|---|
| 1 | for-in This loop performs a set of statements for each item in a range, sequence, collection, or progression. | 
| 2 | while loop Repeats a statement or group of statements while a given condition is true. It tests the condition before executing the loop body. | 
| 3 | repeat...while loop Like a while statement, except that it tests the condition at the end of the loop body. | 
Loop control statements change execution from its normal sequence. When execution leaves a scope, all automatic objects that were created in that scope are destroyed.
Swift 4 supports the following control statements. Click the following links to check their detail.
| Sr.No | Control Statement & Description | 
|---|---|
| 1 | continue statement This statement tells a loop to stop what it is doing and start again at the beginning of the next iteration through the loop. | 
| 2 | break statement Terminates the loop statement and transfers execution to the statement immediately following the loop. | 
| 3 | fallthrough statement The fallthrough statement simulates the behavior of Swift 4 switch to C-style switch. |