Writing a simple for loop in Swift results in error

Question

I have the following code:

let something = 5

for (var i = 1; i< something; i++)
{

}

I get the following error:

braced block in unused closure!!

There is something wrong with the "something" variable I am using above. Any ideas?

UPDATE:

And this works:

 for var i = 1; i<=noOfTimes;i++
    {
        println("Hello World")
    }

Could it have anything to do with the fact that your first example has a closure with no actual code in it? — engineersmnky
– engineersmnky, Commented Sep 7, 2014 at 0:36

Imanou Petit · Accepted Answer · 2015-02-19 17:27:58Z

2

In your for loop, put a space between i and < or remove the space between < and something. The good syntaxes are: i < something and i<something.

This is the result of some powerful features in Swift: prefix, postfix & compound operators.

edited Feb 19, 2015 at 17:27

answered Sep 7, 2014 at 0:39

Imanou Petit

93k31 gold badges268 silver badges223 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Matt Gibson Over a year ago

@Zaph Well, it's defined that way in the Swift book; see the bit about whitespace in the Operators section of the Lexical Structure chapter. It's the way the compiler determines the difference between a postfix operator and a binary operator here (as in Swift, "i<" might be "i" with the postfix operator "<" applied.)

zaph Over a year ago

The point is that it is a poor language design when such a minor change causes a major change in program execution. It is a flaw in the design of the language.

GoZoner · Accepted Answer · 2014-09-07 17:22:01Z

0

Swift supports two syntaxes for for:

for <identifier> in <collection> { <statements> }

or

for <initialization>; <condition>; <increment> { <statements> }

Neither of them require parenthesis around the for specification.

answered Sep 7, 2014 at 17:22

GoZoner

70.8k20 gold badges100 silver badges148 bronze badges

Comments

Steve Rosenberg · Accepted Answer · 2014-09-07 20:44:48Z

0

You are missing a space between i and <. The following works.

let something = 5

for (var i = 1; i < something; i++)
{

}

answered Sep 7, 2014 at 20:44

Steve Rosenberg

19.5k7 gold badges48 silver badges53 bronze badges

Collectives™ on Stack Overflow

Writing a simple for loop in Swift results in error

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related