multiply int with data input in textfield result in label

Question

int Bonus = .3 (need percentage this equals 30%)

label = (textfield * Bonus)

New to Objective-C, standing by if more clarifications is needed.

update: SOLVED! Solution:

HERE IS .h file:

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController {

 IBOutlet UILabel *label;
 IBOutlet UITextField *textfield;
}


- (IBAction)save:(id)sender;

@end

Here is .m file

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController





- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)save:(id) sender {

    float x = ([textfield.text floatValue]);
    float bonus = .3;
    float result;
    result = x * bonus / 10; 

// Divide by 10 to keep it percentage based




    label.text = [[NSString alloc] initWithFormat:@"%.2f", result];

Thanks for everyones help! Especially Xu Yin!!

You need to add more informations whenever you ask for an answer on stackoverflow. — jbouaziz, Feb 07 '14 at 01:01
last time i was told i had to much information and it wasnt straight to the point.... — Ouch, Feb 07 '14 at 02:01
Change `int Bonus` to `float Bonus` otherwise your result will always be 0. — rmaddy, Feb 07 '14 at 02:55

Xu Yin · Accepted Answer · 2014-02-07T01:35:29.233

1

I agree with pacman321, maybe try to add some more information next time..

looks like your questions is:

//1.> "convert NSString to number" 
float value = [textfield.text floatValue];

//2.> do the math 
value = value * Bonus; //Could also be value *= Bonus;

//3.> Convert number back to NSString
label.text = [NSString stringWithFormat:@"%f", value];

I think that's all you need ,but some suggestions here: make sure your textfield will only have numerical value. and may need to pay attention to how much digits you want to display in the label.

edited Feb 07 '14 at 01:35

answered Feb 07 '14 at 01:09

Xu Yin

3,932
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FYI - the 2nd line can simply be `value *= Bonus;`. – rmaddy Feb 07 '14 at 01:31
@rmaddy you are right, mine maybe slightly easier for him to understand, but i will add yours to my answer. Thanks! – Xu Yin Feb 07 '14 at 01:35
thanks, can you look at my update i still have issues? – Ouch Feb 07 '14 at 02:47
@Ouch you use int instead of float for you bonus, int will ignore the decimal places, so your 0.3 --> 0 in this case. – Xu Yin Feb 07 '14 at 03:30
yea i got that figured out :) thanks. I have a question though, im not seeing it actually show the total result? do i need to specify total some how? – Ouch Feb 07 '14 at 03:53
for some reason the label.text = [NSString stringWithFormat:@"%f", value]; comes up with an error when trying to run. – Ouch Feb 07 '14 at 18:58
I tried what someone else recommended as well, but for some reason i cant get it to display..i posted the code under the last UPDATE: – Ouch Feb 07 '14 at 19:01
here is the error: @autoreleasepool { return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class])); } – Ouch Feb 07 '14 at 19:05
maybe you can set an breakout at all the exceptions ,and see where the code stops, i am pretty sure the code i sent you won't cause this problem.. – Xu Yin Feb 07 '14 at 19:11
libc++abi.dylib: terminating with uncaught exception of type NSException – Ouch Feb 07 '14 at 19:23
for that, i can't help you with the code you paste, it seems fine for me. i did a quick search, maybe you can take a look at this post http://stackoverflow.com/questions/7855627/app-crashes-while-loading-with-error-in-main-m – Xu Yin Feb 07 '14 at 19:26
Maybe too much chat here, can you start another question and paste both your .h file code and .m file? – Xu Yin Feb 07 '14 at 20:21
@Xu Yin! Thanks for all your help! i was missing key information in my .h file that was vital! – Ouch Feb 07 '14 at 21:50

score 0 · Answer 2 · answered Feb 07 '14 at 01:00

0

It's all explained there https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/Strings/Articles/FormatStrings.html

textfield.text = [NSString stringWithFormat:@"%d%%", Bonus * 100]

answered Feb 07 '14 at 01:00

jbouaziz

1,484
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2

This is not what the OP wants. – rmaddy Feb 07 '14 at 01:32
[Answers containing only links are rarely good answers.](http://meta.stackexchange.com/questions/8231/are-answers-that-just-contain-links-elsewhere-really-good-answers) Links rot, for one thing, and for another, people may not understand the link and a second explanation may help. – kojiro Feb 08 '14 at 20:24

multiply int with data input in textfield result in label

2 Answers2