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How to Extract a Numerical Value from a String?

开发者 https://www.devze.com 2022-12-31 18:52 出处:网络
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

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 *lo开发者_运维知识库gString = [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".


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];


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

Related questions

  • Best regex library for iphone sdk app?

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


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!


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.


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])];
0

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