Swift Loops

Swift Loop Statements

Swift Loop statements are used to execute a set of statements repeatedly based on a condition or for each element in a collection. Swift provides following looping statements.

• Swift For Loop
• Swift While Loop
• Swift Repeat While Loop

These looping statements can be controlled to break out or skip for an iteration using the following statements. These are called Loop Control Statements.

• Swift Break
• Swift Continue

The following are some special scenarios and examples that involve looping statements.

• Swift Infinite While Loop

For Loop

In the following example, we use for loop to iterate over the elements of an array.

main.swift

var nums:[Int] = [ 2, 4, 6, 8 ]
 
for x in nums {
   print( x )
}

Output

2
4
6
8
Program ended with exit code: 0

While Loop

In the following example, we use while loop to execute a set of statements 5 times in a loop.

main.swift

var i = 1
 
while i <= 5 {
   print("\(i) Hello World")
   i = i + 1
}

Output

1 Hello World
2 Hello World
3 Hello World
4 Hello World
5 Hello World
Program ended with exit code: 0

Repeat While Loop

In the following example, we use repeat while loop to execute a set of statements while the value of i is less than five.

main.swift

var i = 1
 
repeat {
   print("\(i) Hello World")
   i = i + 1
} while( i < 5 )

Output

1 Hello World
2 Hello World
3 Hello World
4 Hello World
Program ended with exit code: 0

Break Statement

Break statement is used to exit a loop. In the following example, we exit for loop when the element is 6.

main.swift

var nums:[Int] = [ 2, 4, 6, 8 ]
 
for x in nums {
    if x == 6 {
        break
    }
   print( x )
}

Output

2
4
Program ended with exit code: 0

Continue Statement

Continue statement is used to skip that iteration of a loop and continue with next iterations. In the following example, we continue with next iterations of for loop when the element is 6.

main.swift

var nums:[Int] = [ 2, 4, 6, 8 ]
 
for x in nums {
    if x == 6 {
        continue
    }
   print( x )
}

Output

2
4
8
Program ended with exit code: 0

Conclusion

In this Swift Tutorial, we have learned about Swift Loops and Loop Control statements with the help of examples.