---
title: "Objective-C : Numbers"  
description: "In Objective-C programming language, in order to save the basic data types like int, float, bool in object form.  Objective-C provides a range of meth"  
author: "Tarun Kumar"  
published: 2015-07-09  
updated: 2017-11-30  
canonical: https://www.mindstick.com/articles/1814/objective-c-numbers  
category: "iphone"  
tags: ["iphone", "ios", "objective c"]  
reading_time: 6 minutes  

---

# Objective-C : Numbers

Previously we learn Constants in [Objective C](https://www.mindstick.com/blog/10914/objective-c-data-type-enum): Objective-C : Constants\

In Objective-C [programming language](https://www.mindstick.com/articles/332896/top-5-programming-languages-for-ios-app-development), in order to save the basic data types like int, float, bool in object form.

Objective-C provides a range of methods to work with NSNumber and important ones are listed in following table:

| ##### S.N. | ##### Method and Description |
| --- | --- |
| 1 | + (NSNumber *)numberWithBool:(BOOL)value *Creates and returns an NSNumber object containing a given value, treating it as a BOOL.* |
| 2 | *+ (NSNumber *)numberWithChar:(char)value* *Creates and returns an NSNumber object containing a given value, treating it as a signed char.* |
| 3 | + (NSNumber *)numberWithDouble:(double)value *Creates and returns an NSNumber object containing a given value, treating it as a double.* |
| 4 | *+ (NSNumber *)numberWithFloat:(float)value* *Creates and returns an NSNumber object containing a given value, treating it as a float.* |
| 5 | *+ (NSNumber *)numberWithInt:(int)value* *Creates and returns an NSNumber object containing a given value, treating it as a signed int.* |
| 6 | *+ (NSNumber *)numberWithInteger:(NSInteger)value* *Creates and returns an NSNumber object containing a given value, treating it as an NSInteger.* |
| 7 | - (BOOL)boolValue *Returns the receiver's value as a BOOL.* |
| 8 | - (char)charValue *Returns the receiver's value as a char.* |
| 9 | - (double)doubleValue *Returns the receiver's value as a double.* |
| 10 | - (float)floatValue *Returns the receiver's value as a float.* |
| 11 | - (NSInteger)integerValue *Returns the receiver's value as an NSInteger.* |
| 12 | - (int)intValue *Returns the receiver's value as an int.* |
| 13 | - (NSString *)stringValue *Returns the receiver's value as a human-readable string.* |

*NSNumber* is a subclass of NSValue that offers a value as any C scalar (numeric) type. It defines a set of methods specifically for setting and accessing the value as a signed or unsigned char, short int, int, long int, long long int, float, or double or as a BOOL. **(**Note that number objects do not necessarily preserve the type they are created with**.)** It also defines a compare: [method to determine](https://www.mindstick.com/forum/12826/how-do-i-write-a-method-to-determine-the-highest-value-in-an-array) the ordering of two *NSNumber* objects.

##### \
Subclassing Notes

\
As with any class cluster, subclasses of NSNumber must override the primitive methods of its superclass, NSValue. In addition, there are two [requirements](https://www.mindstick.com/articles/12850/drivers-license-requirements) around the data type your subclass represents:\

1. Your [implementation](https://answers.mindstick.com/qa/44913/who-is-the-minister-of-statistics-and-programme-implementation) of objCType must return one of “c”, “C”, “s”, “S”, “i”, “I”, “l”, “L”, “q”, “Q”, “f”, and “d”. This is required for the other methods of NSNumber to behave correctly.
2. Your subclass must override the accessor method that corresponds to the declared type—for example, [if your](https://yourviews.mindstick.com/view/83528/what-to-do-if-your-eye-glasses-don-t-fit) implementation of objCType returns “i”, you must override intValue.

*For example, we can extend our example to retrieve and display the value stored in our number object as follows:*

```
#import <Foundation/Foundation.h>int main(){  NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];  NSNumber *myFloat;  float floatvalue;  myFloat = [NSNumber numberWithDouble: 10.09];  floatvalue = [myFloat floatValue];  NSLog (@"Value = %f", floatvalue);  [pool drain];  return 0;}
```

Now when we compile and run the program, we will get the following result.

*```
2015-07-09 03:09:24.786 demo[19264] Value = 10.090000
```*

\

Note that the method used to retrieve the value stored in a number object must match the method used to store the object. An attempt, for example, to retrieve a char from an object initialized as double will provide an unexpected result.\

##### Comparing Number Objects

\

To compare the values stored in two number objects it is necessary to use either the *isEqualToNumber* or compare methods. These are both [instance variables](https://www.mindstick.com/forum/34631/instance-variables-and-class-variables), and as such are called on one object instance, passing through the second object as an argument.

*isEqualToNumber* returns a Boolean value depending on whether the two objects contain the same numbers. For example:

```
#import <Foundation/Foundation.h>int main(){  NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];  NSNumber *myFloat1;  NSNumber *myFloat2;  myFloat1 = [NSNumber numberWithDouble: 10.09];  myFloat2 = [NSNumber numberWithDouble: 10.08];  if ([myFloat1 isEqualToNumber: myFloat2])        NSLog (@"Numbers are equal");  else        NSLog (@"Numbers are not equal");  [pool drain];  return 0;}
```

Now when we compile and run the program, we will get the following result.

*```
2015-07-09 03:13:02.438 demo[21162] Numbers are not equal
```*

The *compare* method is used when you need to know whether one number is less than, greater than or equal to another when those numbers are held in number objects. The [method returns](https://www.mindstick.com/forum/12904/main-method-returns-if-submethod-has-stoped-by-return-in-c-sharp) the result of the comparison in the form of an *NSComparisonResult* enumeration. Possible settings are *NSOrderedSame* if the numbers are equal, *NSOrderedAscending* is the value stored in the first object is less than the number stored in the second and *NSOrderedDescending* if the opposite is true:

```
#import <Foundation/Foundation.h>int main(){  NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];  NSNumber *myFloat1;  NSNumber *myFloat2;  myFloat1 = [NSNumber numberWithDouble: 10.09];   myFloat2 = [NSNumber numberWithDouble: 10.08];   NSComparisonResult result;   result = [myFloat1 compare: myFloat2];  if (result == NSOrderedSame)     NSLog(@"Numbers are equal");  else if (result == NSOrderedAscending)     NSLog(@"Float1 is less than Float2");  else if (result == NSOrderedDescending)     NSLog(@"Float1 is greater than Float2");       [pool drain];  return 0;}
```

Now when we compile and run the program, we will get the following result.

*```
2015-07-09 03:14:13.688 demo[21740] Float1 is greater than Float2
```*

##### Getting the Number Object Value as a String

In order to convert the value stored in a number object to a string, the *stringValue* instance method is provided by the NSNumber class. This method returns the current value as a [string object](https://www.mindstick.com/blog/383/javascript-string-object) (for more information on string objects refer to Working with String Objects in Objective-C):

\

*```
#import <Foundation/Foundation.h>int main(){  NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];  NSNumber *myFloat;  NSString *myString;        myFloat = [NSNumber numberWithDouble: 10.09];  myString = [myFloat stringValue];  NSLog (@"Number as string is %@", myString);       [pool drain];  return 0;}
```*

Now when we compile and run the program, we will get the following result.

```
2015-07-09 03:16:07.085 demo[22825] Number as string is 10.09
```

#####

##### NSNumber Literals

\

##### Previously:

\

NSNumber *number;

number = [NSNumber numberWithChar:'X'];

number = [NSNumber numberWithInt:12345];

number = [NSNumber numberWithUnsignedLong:12345ul];

number = [NSNumber numberWithLongLong:12345ll];

number = [NSNumber numberWithFloat:123.45f];

number = [NSNumber numberWithDouble:123.45];

number = [NSNumber numberWithBool:YES];

###### \

###### \

##### Now:

\

NSNumber *number;

number = @'X';

number = @12345;

number = @12345ul;

number = @12345ll;

number = @123.45f;

number = @123.45;

number = @YES;

---

Original Source: https://www.mindstick.com/articles/1814/objective-c-numbers

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