I am having the user enter into a textfield a number, say 900000. It is then formatted for decimal and shows on the screen as 900,000. When I try to extract the numeric value from the formatted textfield, the number returned is 900. Suggestions?
You could prior to converting to a number delete the , with
stringByReplacingOccurrencesOfString:#"," withString:#""
But this will not work in much of the world where a ' is used as the decimal point.
Better to use an NSNumberFormatter:
NSNumberFormatter *numberFormatter = [NSNumberFormatter new];
numberFormatter.numberStyle = NSNumberFormatterDecimalStyle;
NSNumber *numberObject = [numberFormatter numberFromString:#"900,000"];
NSLog(#"numberObject: %#", numberObject);
int numberInt = [numberObject intValue];
NSLog(#"numberInt: %d", numberInt);
Output:
numberObject: 900000
numberInt: 900000
have you tried removing the comma?
str = [str stringByReplacingOccurrencesOfString:#","
withString:#""];
int value = [str intValue];
I need to print a float value in area of limited width most efficiently. I'm using an NSNumberFormatter, and I set two numbers after the decimal point as the default, so that when I have a number like 234.25 it is printed as is: 234.25. But when I have 1234.25 I want it to be printed as: 1234.3, and 11234.25 should be printed 11234.
I need a maximum of two digits after the point, and a maximum of five digits overall if I have digits after the point, but it also should print more than five digits if the integer part has more.
I don't see ability to limit the total number of digits in NSNumberFormatter. Does this mean that I should write my own function to format numbers in this way? If so, then what is the correct way of getting the count of digits in the integer and fractional parts of a number? I would also prefer working with CGFLoat, rather than NSNumber to avoid extra type conversions.
You're looking for a combination of "maximum significant digits" and "maximum fraction digits", along with particular rounding behavior. NSNumberFormatter is equal to the task:
float twofortythreetwentyfive = 234.25;
float onetwothreefourtwentyfive = 1234.25;
float eleventwothreefourtwentyfive = 11234.25;
NSNumberFormatter * formatter = [[NSNumberFormatter alloc] init];
[formatter setUsesSignificantDigits:YES];
[formatter setMaximumSignificantDigits:5];
[formatter setMaximumFractionDigits:2];
[formatter setRoundingMode:NSNumberFormatterRoundCeiling];
NSLog(#"%#", [formatter stringFromNumber:[NSNumber numberWithFloat:twofortythreetwentyfive]]);
NSLog(#"%#", [formatter stringFromNumber:[NSNumber numberWithFloat:onetwothreefourtwentyfive]]);
NSLog(#"%#", [formatter stringFromNumber:[NSNumber numberWithFloat:eleventwothreefourtwentyfive]]);
Result:
2012-04-26 16:32:04.481 SignificantDigits[11565:707] 234.25
2012-04-26 16:32:04.482 SignificantDigits[11565:707] 1234.3
2012-04-26 16:32:04.483 SignificantDigits[11565:707] 11235
Code :
#define INTPARTSTR(X) [NSString stringWithFormat:#"%d",(int)X]
#define DECPARTSTR(X) [NSString stringWithFormat:#"%d",(int)(((float)X-(int)X)*100)]
- (NSString*)formatFloat:(float)f
{
NSString* result;
result = [NSString stringWithFormat:#"%.2f",f];
if ([DECPARTSTR(f) isEqualToString:#"0"]) return INTPARTSTR(f);
if ([INTPARTSTR(f) length]==5) return INTPARTSTR(f);
if ([result length]>5)
{
int diff = (int)[result length]-7;
NSString* newResult = #"";
for (int i=0; i<[result length]-diff-1; i++)
newResult = [newResult stringByAppendingFormat:#"%c",[result characterAtIndex:i]];
return newResult;
}
return result;
}
Testing it :
- (void)awakeFromNib
{
NSLog(#"%#",[self formatFloat:234.63]);
NSLog(#"%#",[self formatFloat:1234.65]);
NSLog(#"%#",[self formatFloat:11234.65]);
NSLog(#"%#",[self formatFloat:11234]);
}
Output :
2012-04-26 19:27:24.429 newProj[1798:903] 234.63
2012-04-26 19:27:24.432 newProj[1798:903] 1234.6
2012-04-26 19:27:24.432 newProj[1798:903] 11234
2012-04-26 19:27:24.432 newProj[1798:903] 11234
Here is how I implemented this in my code. I don't know how efficient it is, I hope not bad.
So I create a global NSNumberFormatter
NSNumberFormatter* numFormatter;
and initialize it somewhere:
numFormatter=[[NSNumberFormatter alloc]init];
Then I format number with the following function:
- (NSString*)formatFloat:(Float32)number withOptimalDigits:(UInt8)optimalDigits maxDecimals:(UInt8)maxDecimals
{
NSString* result;
UInt8 intDigits=(int)log10f(number)+1;
NSLog(#"Formatting %.5f with maxDig: %d maxDec: %d intLength: %d",number,optimalDigits,maxDecimals,intDigits);
numFormatter.maximumFractionDigits=maxDecimals;
if(intDigits>=optimalDigitis-maxDecimals) {
numFormatter.usesSignificantDigits=YES;
numFormatter.maximumSignificantDigits=(intDigits>optimalDigits)?intDigits:optimalDigits;
} else {
numFormatter.usesSignificantDigits=NO;
}
result = [numFormatter stringFromNumber:[NSNumber numberWithFloat:number]];
return result;
}
Is this a bug when using maximumFractionDigits and maximumSignificantDigits together on NSNumberForamtter on iOS 8?
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
formatter.maximumFractionDigits = 2;
formatter.maximumSignificantDigits = 3;
NSLog(#"%#", [formatter stringFromNumber:#(0.3333)]); // output 0.333 expected 0.33
It works fine if I only use maximumFractionDigits
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
formatter.maximumFractionDigits = 2;
NSLog(#"%#", [formatter stringFromNumber:#(0.3333)]); // output expected .33
NSNumberFormatter maximumFractionDigits and maximumSignificantDigits bug
I'm trying to code a calculator with XCode, but then I saw that Numbers with a comma are just cutted of after the comma.
I am getting the Numbers with this code out of the textfield.
-(IBAction)Additionbutton:(id)sender{
NSString *firstString = field1.text;
NSString *secondString = field2.text;
float num1;
float num2;
float output;
num1 = [firstString floatValue];
num2 = [secondString floatValue];
output = num1 + num2
Solutionfield.text = [ [NSString alloc] initWithFormat:#"%.2f",output] ;
Is it possible to set the calculation that way, that it is able to handle points AND commas or do I have to convert them and if so, how can I do this?
Thank you :)
Maybe you should use: NSNumberFormatter
How to convert an NSString into an NSNumber
I have experienced the same thing this morning, following solution worked for me:
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
NSNumber *aNumber = [NSNumber numberWithFloat:[[yourFloatAsString stringByReplacingOccurrencesOfString:#"," withString:#"" ] floatValue]];
[numberFormatter setNumberStyle:kCFNumberFormatterDecimalStyle];
NSString *formattedNumber;
formattedNumber = [numberFormatter stringFromNumber:aNumber];
NSLog(#"formattedNumber: %#", formattedNumber);
Obviously not the most efficient solution possible. It works, but if you have some time I strongly suggest you to have a look at NSNumberFormatter Class Reference
How do I convert a string to a float in Objective-C?
I am trying to multiply a couple of strings I am getting back from JSON:
float subTotal = [[[[purchaseOrderItemsJSON objectAtIndex:i] objectAtIndex:j] objectForKey:#"Price"] floatValue];
NSLog(#"%#", subTotal);
This gives me: (null) in the console. I know that there is a valid string coming out of that array because I am already using it to display its value in a label.
your_float = [your_string floatValue];
EDIT:
try this:
NSLog(#"float value is: %f", your_float);
The proper way of doing this is
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
numberFormatter.numberStyle = NSNumberFormatterDecimalStyle;
float value = [numberFormatter numberFromString:#"32.12"].floatValue;
How can I convert a NSString containing a number of any primitive data type (e.g. int, float, char, unsigned int, etc.)? The problem is, I don't know which number type the string will contain at runtime.
I have an idea how to do it, but I'm not sure if this works with any type, also unsigned and floating point values:
long long scannedNumber;
NSScanner *scanner = [NSScanner scannerWithString:aString];
[scanner scanLongLong:&scannedNumber];
NSNumber *number = [NSNumber numberWithLongLong: scannedNumber];
Thanks for the help.
Use an NSNumberFormatter:
NSNumberFormatter *f = [[NSNumberFormatter alloc] init];
f.numberStyle = NSNumberFormatterDecimalStyle;
NSNumber *myNumber = [f numberFromString:#"42"];
If the string is not a valid number, then myNumber will be nil. If it is a valid number, then you now have all of the NSNumber goodness to figure out what kind of number it actually is.
You can use -[NSString integerValue], -[NSString floatValue], etc. However, the correct (locale-sensitive, etc.) way to do this is to use -[NSNumberFormatter numberFromString:] which will give you an NSNumber converted from the appropriate locale and given the settings of the NSNumberFormatter (including whether it will allow floating point values).
Objective-C
(Note: this method doesn't play nice with difference locales, but is slightly faster than a NSNumberFormatter)
NSNumber *num1 = #([#"42" intValue]);
NSNumber *num2 = #([#"42.42" floatValue]);
Swift
Simple but dirty way
// Swift 1.2
if let intValue = "42".toInt() {
let number1 = NSNumber(integer:intValue)
}
// Swift 2.0
let number2 = Int("42')
// Swift 3.0
NSDecimalNumber(string: "42.42")
// Using NSNumber
let number3 = NSNumber(float:("42.42" as NSString).floatValue)
The extension-way
This is better, really, because it'll play nicely with locales and decimals.
extension String {
var numberValue:NSNumber? {
let formatter = NumberFormatter()
formatter.numberStyle = .decimal
return formatter.number(from: self)
}
}
Now you can simply do:
let someFloat = "42.42".numberValue
let someInt = "42".numberValue
For strings starting with integers, e.g., #"123", #"456 ft", #"7.89", etc., use -[NSString integerValue].
So, #([#"12.8 lbs" integerValue]) is like doing [NSNumber numberWithInteger:12].
You can also do this:
NSNumber *number = #([dictionary[#"id"] intValue]]);
Have fun!
If you know that you receive integers, you could use:
NSString* val = #"12";
[NSNumber numberWithInt:[val intValue]];
Here's a working sample of NSNumberFormatter reading localized number NSString (xCode 3.2.4, osX 10.6), to save others the hours I've just spent messing around. Beware: while it can handle trailing blanks ("8,765.4 " works), this cannot handle leading white space and this cannot handle stray text characters. (Bad input strings: " 8" and "8q" and "8 q".)
NSString *tempStr = #"8,765.4";
// localization allows other thousands separators, also.
NSNumberFormatter * myNumFormatter = [[NSNumberFormatter alloc] init];
[myNumFormatter setLocale:[NSLocale currentLocale]]; // happen by default?
[myNumFormatter setFormatterBehavior:NSNumberFormatterBehavior10_4];
// next line is very important!
[myNumFormatter setNumberStyle:NSNumberFormatterDecimalStyle]; // crucial
NSNumber *tempNum = [myNumFormatter numberFromString:tempStr];
NSLog(#"string '%#' gives NSNumber '%#' with intValue '%i'",
tempStr, tempNum, [tempNum intValue]);
[myNumFormatter release]; // good citizen
I wanted to convert a string to a double. This above answer didn't quite work for me. But this did: How to do string conversions in Objective-C?
All I pretty much did was:
double myDouble = [myString doubleValue];
Thanks All! I am combined feedback and finally manage to convert from text input ( string ) to Integer. Plus it could tell me whether the input is integer :)
NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
[f setNumberStyle:NSNumberFormatterDecimalStyle];
NSNumber * myNumber = [f numberFromString:thresholdInput.text];
int minThreshold = [myNumber intValue];
NSLog(#"Setting for minThreshold %i", minThreshold);
if ((int)minThreshold < 1 )
{
NSLog(#"Not a number");
}
else
{
NSLog(#"Setting for integer minThreshold %i", minThreshold);
}
[f release];
I think NSDecimalNumber will do it:
Example:
NSNumber *theNumber = [NSDecimalNumber decimalNumberWithString:[stringVariable text]]];
NSDecimalNumber is a subclass of NSNumber, so implicit casting allowed.
What about C's standard atoi?
int num = atoi([scannedNumber cStringUsingEncoding:NSUTF8StringEncoding]);
Do you think there are any caveats?
You can just use [string intValue] or [string floatValue] or [string doubleValue] etc
You can also use NSNumberFormatter class:
you can also do like this code 8.3.3 ios 10.3 support
[NSNumber numberWithInt:[#"put your string here" intValue]]
NSDecimalNumber *myNumber = [NSDecimalNumber decimalNumberWithString:#"123.45"];
NSLog(#"My Number : %#",myNumber);
Try this
NSNumber *yourNumber = [NSNumber numberWithLongLong:[yourString longLongValue]];
Note - I have used longLongValue as per my requirement. You can also use integerValue, longValue, or any other format depending upon your requirement.
Worked in Swift 3
NSDecimalNumber(string: "Your string")
I know this is very late but below code is working for me.
Try this code
NSNumber *number = #([dictionary[#"keyValue"] intValue]]);
This may help you. Thanks
extension String {
var numberValue:NSNumber? {
let formatter = NumberFormatter()
formatter.numberStyle = .decimal
return formatter.number(from: self)
}
}
let someFloat = "12.34".numberValue