How to Extract a Numerical Value from a String?

Question

Is it possible to extract a number from a string. For example, I have a string:

my name is shishir and my number is 98890876478

Can I extract on 98890876478 from the above string?

Or if my string is:

my name is shishir and my number is XXX98890876478XXX

In this condition can I extract `98890876478", which is in between of XXX.

Is it possible to do this?

I am getting a message from a server which should be in the format as above, and I need the numeric value for further operations

Edit:

Here's the code I'm trying to use:

NSString *logString = [NSString stringWithFormat:@"%@",theXML]; 
NSString *digits = [logString stringByTrimmingCharactersInSet:[[NSCharacterSet decimalDigitCharacterSet] invertedSet]]; 
NSLog(@"Message id: %i", [digits intValue]);

which outputs:

2010-05-21 16:37:07.092 sms[5311:207] OK: message-ID XXX110103468XXX
2010-05-21 16:37:07.851 sms[5311:207] Message id: 2

I think its returning two because size==2. I need to retrieve the value between the "XXX".

ITS NOT giving the proper output,i posted my console's output,u can review it. regards shishir — Shishir.bobby, May 21 '10 at 13:51

score 7 · Answer 1 · answered May 21 '10 at 10:35

7

I think what you need is NSScanner, this allows you to take out parts of the string.

e.g.

int n;
NSScanner * scanner = [[NSScanner alloc] initWithString:@"Your string 1234"];
[scanner scanInt:&n];

answered May 21 '10 at 10:35

AndersK

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This is the best approach because using `-[NSString intValue]` can be thrown off by locale. – TechZen May 21 '10 at 11:58

score 1 · Answer 2 · answered Dec 04 '14 at 23:19

Self contained solution:

+ (NSString *)extractNumberFromText:(NSString *)text
{
  NSCharacterSet *nonDigitCharacterSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
  return [[text componentsSeparatedByCharactersInSet:nonDigitCharacterSet] componentsJoinedByString:@""];
}

Handles the following cases:

@"1234" → @"1234"
@"001234" → @"001234"
@"leading text get removed 001234" → @"001234"
@"001234 trailing text gets removed" → @"001234"
@"a0b0c1d2e3f4" → @"001234"

Hope this helps!

score 1 · Answer 3 · edited May 23 '17 at 12:34

1

You can use regex for this: you want to match \d+, that is, a non-zero sequence of digits.

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Otherwise, you can just manually go through the characters in the string and find any contiguous sequence of digits.

edited May 23 '17 at 12:34

Community

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1

answered May 21 '10 at 10:30

polygenelubricants

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But watch out for users with digits in their usernames... Better look for the "my number is" string first, and start scanning from there. – David Gelhar May 21 '10 at 10:38

score 0 · Answer 4 · edited May 23 '17 at 12:18

stringByTrimmingCharactersInSet just remove character at the end or beginning of a string.

ex.: "abc 10 cd" -> 10 (it will work)

ex.: "abc 10 a 1" -> "10 a 1" (it will not work)

Using regex seem a better idea.

iphone sdk - Remove all characters except for numbers 0-9 from a string

EDIT:

Check not the accepted answer but the one with more than 50 votes

NSString * number = @"(555) 555-555 Office";
NSString * strippedNumber = [number stringByReplacingOccurrencesOfString:@"[^0-9]" withString:@"" options:NSRegularExpressionSearch range:NSMakeRange(0, [number length])];

Shishir.bobby · Accepted Answer · 2011-11-08T06:16:43.433

0

THIS IS WHAT I FINALLY DONE WITH

NSString *newString = [[theXML componentsSeparatedByCharactersInSet: [[NSCharacterSet decimalDigitCharacterSet] invertedSet]] componentsJoinedByString:@""];
----------------------------------------

NSString *newStr = [newString substringWithRange:NSMakeRange(1, [newString length]-1)];
----------------------------------------

And I am done.

edited Nov 08 '11 at 06:16

answered May 24 '10 at 13:30

Shishir.bobby

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How to Extract a Numerical Value from a String?

Edit:

5 Answers5

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