CODEWITHSUNDEEP
for-loop
thekmc
thekmc

Reputation: 516

For loop is being skipped in Cocoa Touch

I was doing some programming in Cocoa Touch and Objective-C, and now I have a really frustrating problem. I have a method in which there is a for-loop. Yet, every time I run the app in the iOS Simulator, the code in the loop isn't run, and it doesn't stop on any breakpoints within the loop. At first, I thought it was just in the method, but it appears now that it happens anywhere in the code. No for-loops work anywhere in any methods. Here is an example of one of my loops, and if you see anything wrong, I would appreciate the help.

for (int i = 0; i == 3; i++) {
    NSLog(@"This is a test.");
}

This might be something really dumb that I am missing, but I can't see anything that could be causing this. If you need more code, just ask, and thanks in advance!

Upvotes: 0

Views: 491

Answers (5)

Gerald P. Wright
Gerald P. Wright

Reputation: 796

The condition on a for loop causes the loop to run as long as the condition is true.

In the example you cited, the loop will never execute because i started off equal to zero, with the test condition i == 3. Since i == 3 is immediately false, the loop does not run even once.

If your intention was to run the loop until i was three, then the test condition should be i < 3 making the entire for

for (int i = 0; i < 3; i++) {

Another way to think about this is that the loop will continue to run "while i < 3".

I hope this helps.

Upvotes: 5

esqew
esqew

Reputation: 44701

I think your loop should look more like this:

for (int i = 0; i <= 3; i++) {
    NSLog(@"This is a test.");
}

Upvotes: 0

NSResponder
NSResponder

Reputation: 16861

A for loop runs as long as the continuation condition is true. Change "i==3" to "i <= 3".

Upvotes: 1

Seamus Campbell
Seamus Campbell

Reputation: 17906

The second part of a for-loop—in your code, i == 3—is a test that is checked before each iteration of the loop. If the test is false, the loop is ended. Since i is 0 on the first iteration, i == 3 is false.

You probably want either i <= 3 or i < 3 as your conditional.

Upvotes: 1

Tushar Chutani
Tushar Chutani

Reputation: 1560

may be try 

 for(int i = 0; i < 4;i++){
 NSLog("This is a test");
}

Upvotes: 0

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