How to write NSString in a float format? - ios

Question

In My app I have a UITextField. When a user enters text such as 123456 it should appear something like 123,456.00 in the textfield.
The following code is used:
UITextField *txt = [[UITextField alloc]initWithFrame:CGRectMake(300, 120+y*58, 280, 31)];
txt.keyboardType = UIKeyboardTypeDecimalPad;
txt.borderStyle = UITextBorderStyleRoundedRect;
txt.font = [UIFont systemFontOfSize:15];
txt.textAlignment = NSTextAlignmentLeft;
txt.returnKeyType = UIReturnKeyDefault;
txt.delegate = self;
[txt addTarget:self action:#selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
-(void)textFieldDidChange:(UITextField *)theTextField
{
NSString *textFieldText = [theTextField.text stringByReplacingOccurrencesOfString:#"," withString:#""];
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];
NSNumber *number = [formatter numberFromString:textFieldText];
NSString *formattedOutput = [formatter stringFromNumber:number];
theTextField.text=formattedOutput;
}

Answer 1

Use below code
NSString *textFieldText = theTextField.text ;
float f = [theString floatValue];
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];
[formatter setMinimumFractionDigits:2];
[formatter setMaximumFractionDigits:2];
[formatter setLocale:[NSLocale currentLocale]];
NSLog(#"%#", [formatter stringFromNumber:#(f)]);
Set MinimumFractionDigits to 2 & MaximumFractionDigits to 2.Try above code in textFieldDidEndEditing delegate method of textfield.

Answer 2

You are almost close to your solution just few things need enhancement. First you must have to specify the maximum and minimum allowed fractions digits like this:
[formatter setMinimumFractionDigits:2];
[formatter setMaximumFractionDigits:2];
It will fix the *.00 problem, then there is another problem of updating it back to the UI. Since you are setting the textfield text:
theTextField.text=formattedOutput;
It will lose the current position of editing and hence you will lose the ground. e.g.,
You typed 1, the above code will update the textfield with 1.00 and the cursor will move to position 5:
1.00
^^^^^
If you will edit further you won't get the expected result (the text will try to append at the end).
To fix this either you should update the text field when you finish editing using the handler textFieldDidEndEditing or you should use some other control like UILabel to display the formatted result.
Sample Code: (for demo)
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UITextField *txt = [[UITextField alloc]initWithFrame:CGRectMake(20, 120+(3)*58, 280, 31)];
txt.keyboardType = UIKeyboardTypeDecimalPad;
txt.borderStyle = UITextBorderStyleRoundedRect;
txt.font = [UIFont systemFontOfSize:15];
txt.textAlignment = NSTextAlignmentLeft;
txt.returnKeyType = UIReturnKeyDefault;
txt.delegate = self;
[self.view addSubview:txt];
[txt addTarget:self action:#selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
lbl = [[UILabel alloc] initWithFrame:CGRectMake(20, 160+(3)*58, 280, 31)];
[self.view addSubview:lbl];
}
-(void)textFieldDidChange:(UITextField *)theTextField
{
NSString *textFieldText = [theTextField.text stringByReplacingOccurrencesOfString:#"," withString:#""];
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];
[formatter setMinimumFractionDigits:2];
[formatter setMaximumFractionDigits:2];
NSNumber *number = [formatter numberFromString:textFieldText];
NSString *formattedOutput = [formatter stringFromNumber:number];
[lbl setText:formattedOutput];
}

Answer 3

You can set text like this to your textview.
theTextField.text = [NSString stringWithFormat:#"%.02f", floatVal];
Hope this helps.

Answer 4

If you add these two lines to the code snippet you posted:
[formatter setMinimumFractionDigits:2];
[formatter setMaximumFractionDigits:2];
right after the line in which you set the number formatter's style to NSNumberFormatterDecimalStyle, it should give you exactly what you want.
#"123456" would result in #"123,456.00"
and #"1" would result in #"1.00"