How to print or log the value of CGSize object?

Question

I was trying to log (print) the value of CGSize object like this:

CGSize sizeOfTab = CGSizeMake(self.frame.size.width/tabCount, 49);

NSLog(@"size of tab is %@",sizeOfTab);

Is there anything wrong in this code; my app is crashing while control comes to NSLog statement.

Thanks Prasad

NSStringFromCGSize( ) and also NSStringFromCGRect( ) – Fattie Dec 03 '13 at 21:07 — Fattie, Dec 03 '13 at 21:07

visakh7 · Answer 1 · 2011-07-08T08:50:36.680

221

Try this

CGSize sizeOfTab = CGSizeMake(self.frame.size.width/tabCount, 49);
NSLog(@"size of tab is %@",NSStringFromCGSize(sizeOfTab));

The crash occurs because sizeOfTab is not in NSString format.

edited Jul 08 '11 at 08:50

answered Jul 08 '11 at 08:42

visakh7

26,380
8
55
69

3

Cool this is something new i learnt today. +1, but i wont delete my answer :-P. – Praveen S Jul 08 '11 at 08:43
@Praveen: Thanks.. Glad I cud help you to learn something new today... Just returning the favor. I have been and still in the receiving end of such information through SO. – visakh7 Jul 08 '11 at 08:45
1

@7KV7 The crash occurs because `sizeOfTab` is not an object (any object would work, not just a `NSString`). `CGSize` is a struct. – albertamg Jul 08 '11 at 08:49
thanku its working fine, but its displaying {nan, 49}, what is nan? – Prasad Jul 08 '11 at 08:50
@Prasad: nan I think stands for Not a Number. what is tabCount? try logging `self.frame.size.width/tabCount` – visakh7 Jul 08 '11 at 08:52
@7KV7: thanks, Ya if tabCount is zero(0), then its showing nan – Prasad Jul 08 '11 at 08:57
@Prasad: Division by 0 is the problem. As u probably know its not defined hence it shows "nan". – visakh7 Jul 08 '11 at 08:58
This should be the accepted answer. Learned something new :) – michaelk Dec 29 '17 at 07:29

Luke · Accepted Answer · 2014-09-22T18:38:48.350

59

You can call the following to print the value you are after:

NSLog(@"width = %f, height = %f", mySize.width, mySize.height);

edited Sep 22 '14 at 18:38

answered Jul 08 '11 at 08:41

Luke

11,426
43
60
69

score 11 · Answer 3 · edited May 23 '17 at 10:31

As JoeBlow mentioned (I noticed after typing and formatting this answer), there's also the UIKit function, NSStringFromCGSize(), for pretty printing, and its inverse, CGSizeFromString(), for creating a CGSize struct from an NSString object.

Apple documents the string parameter of CGSizeFromString(string) as follows:

A string whose contents are of the form "{w, h}", where w is the width and h is the height. The w and h values can be integer or float values. An example of a valid string is @"{3.0,2.5}". The string is not localized, so items are always separated with a comma.

Example

CGSize size = CGSizeFromString(@"{320,568}");
NSLog(@"Pretty printed size: %@", NSStringFromCGSize(size));

Output

Pretty printed size: {320, 568}

Other Useful Functions (CGGeometry Reference)

CGRectGetHeight()
CGRectGetWidth()

score 6 · Answer 4 · answered Jul 08 '11 at 08:47

6

%@ means you are trying to insert a string. CGSize is not a string, and cannot automagically be converted to one. That's why your app crashes. Instead, you need to log individual properties separately, like

NSLog(@"width is %f, height is %f.", sizeOfTab.width, sizeOfTab.height);

%f is used because the width and height properties are of the type float.

For other format conversions, see the docs: http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Strings/Articles/formatSpecifiers.html

answered Jul 08 '11 at 08:47

Greg

9,068
6
49
91

Welcome to SO. +1 for a detailed answer. – Praveen S Jul 08 '11 at 09:01
Thanks. I had a look around and it's amazing to see how many people never bother looking at the docs before asking a question. I put the link there so we don't get another question asking how to print an _int_. – Greg Jul 08 '11 at 09:20

score 3 · Answer 5 · answered Jul 03 '17 at 09:05

3

Here self.view is the view of UIView Class. You can print any frame with this log.

      NSLog(@"self.view.Frame=%@", NSStringFromCGRect(self.view.frame));

answered Jul 03 '17 at 09:05

Disha

608
7
10

score 3 · Answer 6 · answered Jul 08 '11 at 08:42

3

CGSize has the memebers width and height which are of type CGFloat. You can print them using the following

NSLog(@"Width = %f, height = %f",sizeOfTab.width, sizeofTab.height);

answered Jul 08 '11 at 08:42

Praveen S

10,355
2
43
69

How to print or log the value of CGSize object?

6 Answers6

Example

Output

Other Useful Functions (CGGeometry Reference)